diff --git a/CHANGES.md b/CHANGES.md
index bce3fa158a7..2fe14cd5246 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -6,22 +6,54 @@
 
 <!-- Include any especially major or disruptive changes here -->
 
+This release introduces the new 2024 stable style (#4106), stabilizing the following
+changes:
+
+- Add parentheses around `if`-`else` expressions (#2278)
+- Dummy class and function implementations consisting only of `...` are formatted more
+  compactly (#3796)
+- If an assignment statement is too long, we now prefer splitting on the right-hand side
+  (#3368)
+- Hex codes in Unicode escape sequences are now standardized to lowercase (#2916)
+- Allow empty first lines at the beginning of most blocks (#3967, #4061)
+- Add parentheses around long type annotations (#3899)
+- Standardize on a single newline after module docstrings (#3932)
+- Fix incorrect magic trailing comma handling in return types (#3916)
+- Remove blank lines before class docstrings (#3692)
+- Wrap multiple context managers in parentheses if combined in a single `with` statement
+  (#3489)
+- Fix bug in line length calculations for power operations (#3942)
+- Add trailing commas to collection literals even if there's a comment after the last
+  entry (#3393)
+- When using `--skip-magic-trailing-comma` or `-C`, trailing commas are stripped from
+  subscript expressions with more than 1 element (#3209)
+- Add extra blank lines in stubs in a few cases (#3564, #3862)
+- Accept raw strings as docstrings (#3947)
+- Split long lines in case blocks (#4024)
+- Stop removing spaces from walrus operators within subscripts (#3823)
+- Fix incorrect formatting of certain async statements (#3609)
+- Allow combining `# fmt: skip` with other comments (#3959)
+
 ### Stable style
 
 <!-- Changes that affect Black's stable style -->
 
-### Preview style
-
-<!-- Changes that affect Black's preview style -->
+Several bug fixes were made in features that are moved to the stable style in this
+release:
 
 - Fix comment handling when parenthesising conditional expressions (#4134)
-- Format module docstrings the same as class and function docstrings (#4095)
 - Fix bug where spaces were not added around parenthesized walruses in subscripts,
   unlike other binary operators (#4109)
 - Remove empty lines before docstrings in async functions (#4132)
 - Address a missing case in the change to allow empty lines at the beginning of all
   blocks, except immediately before a docstring (#4130)
 - For stubs, fix logic to enforce empty line after nested classes with bodies (#4141)
+
+### Preview style
+
+<!-- Changes that affect Black's preview style -->
+
+- Format module docstrings the same as class and function docstrings (#4095)
 - Fix crash when using a walrus in a dictionary (#4155)
 - Fix unnecessary parentheses when wrapping long dicts (#4135)
 - Stop normalizing spaces before `# fmt: skip` comments (#4146)
diff --git a/src/black/comments.py b/src/black/comments.py
index 34bff4d812f..ce29049f506 100644
--- a/src/black/comments.py
+++ b/src/black/comments.py
@@ -3,7 +3,7 @@
 from functools import lru_cache
 from typing import Collection, Final, Iterator, List, Optional, Tuple, Union
 
-from black.mode import Mode, Preview
+from black.mode import Mode
 from black.nodes import (
     CLOSING_BRACKETS,
     STANDALONE_COMMENT,
@@ -398,22 +398,18 @@ def _contains_fmt_skip_comment(comment_line: str, mode: Mode) -> bool:
       # noqa:XXX # fmt:skip # a nice line  <-- multiple comments (Preview)
       # pylint:XXX; fmt:skip               <-- list of comments (; separated, Preview)
     """
-    semantic_comment_blocks = (
-        [
-            comment_line,
-            *[
-                _COMMENT_PREFIX + comment.strip()
-                for comment in comment_line.split(_COMMENT_PREFIX)[1:]
-            ],
-            *[
-                _COMMENT_PREFIX + comment.strip()
-                for comment in comment_line.strip(_COMMENT_PREFIX).split(
-                    _COMMENT_LIST_SEPARATOR
-                )
-            ],
-        ]
-        if Preview.single_line_format_skip_with_multiple_comments in mode
-        else [comment_line]
-    )
+    semantic_comment_blocks = [
+        comment_line,
+        *[
+            _COMMENT_PREFIX + comment.strip()
+            for comment in comment_line.split(_COMMENT_PREFIX)[1:]
+        ],
+        *[
+            _COMMENT_PREFIX + comment.strip()
+            for comment in comment_line.strip(_COMMENT_PREFIX).split(
+                _COMMENT_LIST_SEPARATOR
+            )
+        ],
+    ]
 
     return any(comment in FMT_SKIP for comment in semantic_comment_blocks)
diff --git a/src/black/linegen.py b/src/black/linegen.py
index dd296eb801d..a276805f2fe 100644
--- a/src/black/linegen.py
+++ b/src/black/linegen.py
@@ -115,10 +115,8 @@ def line(self, indent: int = 0) -> Iterator[Line]:
             self.current_line.depth += indent
             return  # Line is empty, don't emit. Creating a new one unnecessary.
 
-        if (
-            Preview.improved_async_statements_handling in self.mode
-            and len(self.current_line.leaves) == 1
-            and is_async_stmt_or_funcdef(self.current_line.leaves[0])
+        if len(self.current_line.leaves) == 1 and is_async_stmt_or_funcdef(
+            self.current_line.leaves[0]
         ):
             # Special case for async def/for/with statements. `visit_async_stmt`
             # adds an `ASYNC` leaf then visits the child def/for/with statement
@@ -164,20 +162,19 @@ def visit_default(self, node: LN) -> Iterator[Line]:
     def visit_test(self, node: Node) -> Iterator[Line]:
         """Visit an `x if y else z` test"""
 
-        if Preview.parenthesize_conditional_expressions in self.mode:
-            already_parenthesized = (
-                node.prev_sibling and node.prev_sibling.type == token.LPAR
-            )
+        already_parenthesized = (
+            node.prev_sibling and node.prev_sibling.type == token.LPAR
+        )
 
-            if not already_parenthesized:
-                # Similar to logic in wrap_in_parentheses
-                lpar = Leaf(token.LPAR, "")
-                rpar = Leaf(token.RPAR, "")
-                prefix = node.prefix
-                node.prefix = ""
-                lpar.prefix = prefix
-                node.insert_child(0, lpar)
-                node.append_child(rpar)
+        if not already_parenthesized:
+            # Similar to logic in wrap_in_parentheses
+            lpar = Leaf(token.LPAR, "")
+            rpar = Leaf(token.RPAR, "")
+            prefix = node.prefix
+            node.prefix = ""
+            lpar.prefix = prefix
+            node.insert_child(0, lpar)
+            node.append_child(rpar)
 
         yield from self.visit_default(node)
 
@@ -292,9 +289,7 @@ def visit_match_case(self, node: Node) -> Iterator[Line]:
 
     def visit_suite(self, node: Node) -> Iterator[Line]:
         """Visit a suite."""
-        if (
-            self.mode.is_pyi or Preview.dummy_implementations in self.mode
-        ) and is_stub_suite(node, self.mode):
+        if is_stub_suite(node):
             yield from self.visit(node.children[2])
         else:
             yield from self.visit_default(node)
@@ -308,11 +303,7 @@ def visit_simple_stmt(self, node: Node) -> Iterator[Line]:
             prev_type = child.type
 
         if node.parent and node.parent.type in STATEMENT:
-            if Preview.dummy_implementations in self.mode:
-                condition = is_parent_function_or_class(node)
-            else:
-                condition = self.mode.is_pyi
-            if condition and is_stub_body(node):
+            if is_parent_function_or_class(node) and is_stub_body(node):
                 yield from self.visit_default(node)
             else:
                 yield from self.line(+1)
@@ -320,11 +311,7 @@ def visit_simple_stmt(self, node: Node) -> Iterator[Line]:
                 yield from self.line(-1)
 
         else:
-            if (
-                not (self.mode.is_pyi or Preview.dummy_implementations in self.mode)
-                or not node.parent
-                or not is_stub_suite(node.parent, self.mode)
-            ):
+            if not node.parent or not is_stub_suite(node.parent):
                 yield from self.line()
             yield from self.visit_default(node)
 
@@ -342,11 +329,7 @@ def visit_async_stmt(self, node: Node) -> Iterator[Line]:
                 break
 
         internal_stmt = next(children)
-        if Preview.improved_async_statements_handling in self.mode:
-            yield from self.visit(internal_stmt)
-        else:
-            for child in internal_stmt.children:
-                yield from self.visit(child)
+        yield from self.visit(internal_stmt)
 
     def visit_decorators(self, node: Node) -> Iterator[Line]:
         """Visit decorators."""
@@ -420,10 +403,9 @@ def foo(a: int, b: float = 7): ...
 
         def foo(a: (int), b: (float) = 7): ...
         """
-        if Preview.parenthesize_long_type_hints in self.mode:
-            assert len(node.children) == 3
-            if maybe_make_parens_invisible_in_atom(node.children[2], parent=node):
-                wrap_in_parentheses(node, node.children[2], visible=False)
+        assert len(node.children) == 3
+        if maybe_make_parens_invisible_in_atom(node.children[2], parent=node):
+            wrap_in_parentheses(node, node.children[2], visible=False)
 
         yield from self.visit_default(node)
 
@@ -529,13 +511,7 @@ def __post_init__(self) -> None:
         self.visit_with_stmt = partial(v, keywords={"with"}, parens={"with"})
         self.visit_classdef = partial(v, keywords={"class"}, parens=Ø)
 
-        # When this is moved out of preview, add ":" directly to ASSIGNMENTS in nodes.py
-        if Preview.parenthesize_long_type_hints in self.mode:
-            assignments = ASSIGNMENTS | {":"}
-        else:
-            assignments = ASSIGNMENTS
-        self.visit_expr_stmt = partial(v, keywords=Ø, parens=assignments)
-
+        self.visit_expr_stmt = partial(v, keywords=Ø, parens=ASSIGNMENTS)
         self.visit_return_stmt = partial(v, keywords={"return"}, parens={"return"})
         self.visit_import_from = partial(v, keywords=Ø, parens={"import"})
         self.visit_del_stmt = partial(v, keywords=Ø, parens={"del"})
@@ -576,9 +552,7 @@ def transform_line(
     # We need the line string when power operators are hugging to determine if we should
     # split the line. Default to line_str, if no power operator are present on the line.
     line_str_hugging_power_ops = (
-        (_hugging_power_ops_line_to_string(line, features, mode) or line_str)
-        if Preview.fix_power_op_line_length in mode
-        else line_str
+        _hugging_power_ops_line_to_string(line, features, mode) or line_str
     )
 
     ll = mode.line_length
@@ -688,9 +662,6 @@ def should_split_funcdef_with_rhs(line: Line, mode: Mode) -> bool:
     """If a funcdef has a magic trailing comma in the return type, then we should first
     split the line with rhs to respect the comma.
     """
-    if Preview.respect_magic_trailing_comma_in_return_type not in mode:
-        return False
-
     return_type_leaves: List[Leaf] = []
     in_return_type = False
 
@@ -919,9 +890,6 @@ def _maybe_split_omitting_optional_parens(
         try:
             # The RHSResult Omitting Optional Parens.
             rhs_oop = _first_right_hand_split(line, omit=omit)
-            prefer_splitting_rhs_mode = (
-                Preview.prefer_splitting_right_hand_side_of_assignments in line.mode
-            )
             is_split_right_after_equal = (
                 len(rhs.head.leaves) >= 2 and rhs.head.leaves[-2].type == token.EQUAL
             )
@@ -937,8 +905,7 @@ def _maybe_split_omitting_optional_parens(
             )
             if (
                 not (
-                    prefer_splitting_rhs_mode
-                    and is_split_right_after_equal
+                    is_split_right_after_equal
                     and rhs_head_contains_brackets
                     and rhs_head_short_enough
                     and rhs_head_explode_blocked_by_magic_trailing_comma
@@ -1224,11 +1191,7 @@ def append_to_line(leaf: Leaf) -> Iterator[Line]:
                     trailing_comma_safe and Feature.TRAILING_COMMA_IN_CALL in features
                 )
 
-        if (
-            Preview.add_trailing_comma_consistently in mode
-            and last_leaf.type == STANDALONE_COMMENT
-            and leaf_idx == last_non_comment_leaf
-        ):
+        if last_leaf.type == STANDALONE_COMMENT and leaf_idx == last_non_comment_leaf:
             current_line = _safe_add_trailing_comma(
                 trailing_comma_safe, delimiter_priority, current_line
             )
@@ -1315,11 +1278,7 @@ def normalize_invisible_parens(  # noqa: C901
 
         # Fixes a bug where invisible parens are not properly wrapped around
         # case blocks.
-        if (
-            isinstance(child, Node)
-            and child.type == syms.case_block
-            and Preview.long_case_block_line_splitting in mode
-        ):
+        if isinstance(child, Node) and child.type == syms.case_block:
             normalize_invisible_parens(
                 child, parens_after={"case"}, mode=mode, features=features
             )
@@ -1374,7 +1333,6 @@ def normalize_invisible_parens(  # noqa: C901
                 and child.next_sibling is not None
                 and child.next_sibling.type == token.COLON
                 and child.value == "case"
-                and Preview.long_case_block_line_splitting in mode
             ):
                 # A special patch for "case case:" scenario, the second occurrence
                 # of case will be not parsed as a Python keyword.
@@ -1448,7 +1406,6 @@ def _maybe_wrap_cms_in_parens(
     """
     if (
         Feature.PARENTHESIZED_CONTEXT_MANAGERS not in features
-        or Preview.wrap_multiple_context_managers_in_parens not in mode
         or len(node.children) <= 2
         # If it's an atom, it's already wrapped in parens.
         or node.children[1].type == syms.atom
diff --git a/src/black/lines.py b/src/black/lines.py
index 9eb5785da57..29f87137614 100644
--- a/src/black/lines.py
+++ b/src/black/lines.py
@@ -202,9 +202,7 @@ def _is_triple_quoted_string(self) -> bool:
         value = self.leaves[0].value
         if value.startswith(('"""', "'''")):
             return True
-        if Preview.accept_raw_docstrings in self.mode and value.startswith(
-            ("r'''", 'r"""', "R'''", 'R"""')
-        ):
+        if value.startswith(("r'''", 'r"""', "R'''", 'R"""')):
             return True
         return False
 
@@ -450,14 +448,8 @@ def is_complex_subscript(self, leaf: Leaf) -> bool:
             if subscript_start.type == syms.subscriptlist:
                 subscript_start = child_towards(subscript_start, leaf)
 
-        # When this is moved out of preview, add syms.namedexpr_test directly to
-        # TEST_DESCENDANTS in nodes.py
-        if Preview.walrus_subscript in self.mode:
-            test_decendants = TEST_DESCENDANTS | {syms.namedexpr_test}
-        else:
-            test_decendants = TEST_DESCENDANTS
         return subscript_start is not None and any(
-            n.type in test_decendants for n in subscript_start.pre_order()
+            n.type in TEST_DESCENDANTS for n in subscript_start.pre_order()
         )
 
     def enumerate_with_length(
@@ -567,8 +559,7 @@ def maybe_empty_lines(self, current_line: Line) -> LinesBlock:
         lines (two on module-level).
         """
         form_feed = (
-            Preview.allow_form_feeds in self.mode
-            and current_line.depth == 0
+            current_line.depth == 0
             and bool(current_line.leaves)
             and "\f\n" in current_line.leaves[0].prefix
         )
@@ -582,8 +573,7 @@ def maybe_empty_lines(self, current_line: Line) -> LinesBlock:
             else before - previous_after
         )
         if (
-            Preview.module_docstring_newlines in current_line.mode
-            and self.previous_block
+            self.previous_block
             and self.previous_block.previous_block is None
             and len(self.previous_block.original_line.leaves) == 1
             and self.previous_block.original_line.is_docstring
@@ -640,11 +630,7 @@ def _maybe_empty_lines(self, current_line: Line) -> Tuple[int, int]:
         if previous_def is not None:
             assert self.previous_line is not None
             if self.mode.is_pyi:
-                if (
-                    Preview.blank_line_after_nested_stub_class in self.mode
-                    and previous_def.is_class
-                    and not previous_def.is_stub_class
-                ):
+                if previous_def.is_class and not previous_def.is_stub_class:
                     before = 1
                 elif depth and not current_line.is_def and self.previous_line.is_def:
                     # Empty lines between attributes and methods should be preserved.
@@ -695,18 +681,12 @@ def _maybe_empty_lines(self, current_line: Line) -> Tuple[int, int]:
             and self.previous_line.is_class
             and current_line.is_docstring
         ):
-            if Preview.no_blank_line_before_class_docstring in current_line.mode:
-                return 0, 1
-            return before, 1
+            return 0, 1
 
         # In preview mode, always allow blank lines, except right before a function
         # docstring
-        is_empty_first_line_ok = (
-            Preview.allow_empty_first_line_in_block in current_line.mode
-            and (
-                not current_line.is_docstring
-                or (self.previous_line and not self.previous_line.is_def)
-            )
+        is_empty_first_line_ok = not current_line.is_docstring or (
+            self.previous_line and not self.previous_line.is_def
         )
 
         if (
@@ -736,7 +716,7 @@ def _maybe_empty_lines_for_class_or_def(  # noqa: C901
         if self.previous_line.depth < current_line.depth and (
             self.previous_line.is_class or self.previous_line.is_def
         ):
-            if self.mode.is_pyi or not Preview.allow_empty_first_line_in_block:
+            if self.mode.is_pyi:
                 return 0, 0
             else:
                 return 1 if user_had_newline else 0, 0
@@ -776,10 +756,7 @@ def _maybe_empty_lines_for_class_or_def(  # noqa: C901
             # Don't inspect the previous line if it's part of the body of the previous
             # statement in the same level, we always want a blank line if there's
             # something with a body preceding.
-            elif (
-                Preview.blank_line_between_nested_and_def_stub_file in current_line.mode
-                and self.previous_line.depth > current_line.depth
-            ):
+            elif self.previous_line.depth > current_line.depth:
                 newlines = 1
             elif (
                 current_line.is_def or current_line.is_decorator
@@ -800,11 +777,7 @@ def _maybe_empty_lines_for_class_or_def(  # noqa: C901
             newlines = 1 if current_line.depth else 2
             # If a user has left no space after a dummy implementation, don't insert
             # new lines. This is useful for instance for @overload or Protocols.
-            if (
-                Preview.dummy_implementations in self.mode
-                and self.previous_line.is_stub_def
-                and not user_had_newline
-            ):
+            if self.previous_line.is_stub_def and not user_had_newline:
                 newlines = 0
         if comment_to_add_newlines is not None:
             previous_block = comment_to_add_newlines.previous_block
@@ -859,11 +832,9 @@ def is_line_short_enough(  # noqa: C901
     if not line_str:
         line_str = line_to_string(line)
 
-    width = str_width if Preview.respect_east_asian_width in mode else len
-
     if Preview.multiline_string_handling not in mode:
         return (
-            width(line_str) <= mode.line_length
+            str_width(line_str) <= mode.line_length
             and "\n" not in line_str  # multiline strings
             and not line.contains_standalone_comments()
         )
@@ -872,10 +843,10 @@ def is_line_short_enough(  # noqa: C901
         return False
     if "\n" not in line_str:
         # No multiline strings (MLS) present
-        return width(line_str) <= mode.line_length
+        return str_width(line_str) <= mode.line_length
 
     first, *_, last = line_str.split("\n")
-    if width(first) > mode.line_length or width(last) > mode.line_length:
+    if str_width(first) > mode.line_length or str_width(last) > mode.line_length:
         return False
 
     # Traverse the AST to examine the context of the multiline string (MLS),
@@ -1015,11 +986,7 @@ def can_omit_invisible_parens(
         return False
 
     if delimiter_count == 1:
-        if (
-            Preview.wrap_multiple_context_managers_in_parens in line.mode
-            and max_priority == COMMA_PRIORITY
-            and rhs.head.is_with_or_async_with_stmt
-        ):
+        if max_priority == COMMA_PRIORITY and rhs.head.is_with_or_async_with_stmt:
             # For two context manager with statements, the optional parentheses read
             # better. In this case, `rhs.body` is the context managers part of
             # the with statement. `rhs.head` is the `with (` part on the previous
diff --git a/src/black/mode.py b/src/black/mode.py
index 8ff65c59950..a1519f17bcc 100644
--- a/src/black/mode.py
+++ b/src/black/mode.py
@@ -168,36 +168,15 @@ def supports_feature(target_versions: Set[TargetVersion], feature: Feature) -> b
 class Preview(Enum):
     """Individual preview style features."""
 
-    add_trailing_comma_consistently = auto()
-    blank_line_after_nested_stub_class = auto()
-    blank_line_between_nested_and_def_stub_file = auto()
     hex_codes_in_unicode_sequences = auto()
-    improved_async_statements_handling = auto()
-    multiline_string_handling = auto()
-    no_blank_line_before_class_docstring = auto()
-    prefer_splitting_right_hand_side_of_assignments = auto()
     # NOTE: string_processing requires wrap_long_dict_values_in_parens
     # for https://github.com/psf/black/issues/3117 to be fixed.
     string_processing = auto()
-    parenthesize_conditional_expressions = auto()
-    parenthesize_long_type_hints = auto()
-    respect_magic_trailing_comma_in_return_type = auto()
-    skip_magic_trailing_comma_in_subscript = auto()
-    wrap_long_dict_values_in_parens = auto()
-    wrap_multiple_context_managers_in_parens = auto()
-    dummy_implementations = auto()
-    walrus_subscript = auto()
-    module_docstring_newlines = auto()
-    accept_raw_docstrings = auto()
-    fix_power_op_line_length = auto()
     hug_parens_with_braces_and_square_brackets = auto()
-    allow_empty_first_line_in_block = auto()
-    single_line_format_skip_with_multiple_comments = auto()
-    long_case_block_line_splitting = auto()
-    allow_form_feeds = auto()
     unify_docstring_detection = auto()
-    respect_east_asian_width = auto()
     no_normalize_fmt_skip_whitespace = auto()
+    wrap_long_dict_values_in_parens = auto()
+    multiline_string_handling = auto()
 
 
 class Deprecated(UserWarning):
diff --git a/src/black/nodes.py b/src/black/nodes.py
index 7ee2df2e061..a8869cba234 100644
--- a/src/black/nodes.py
+++ b/src/black/nodes.py
@@ -104,6 +104,7 @@
     syms.trailer,
     syms.term,
     syms.power,
+    syms.namedexpr_test,
 }
 TYPED_NAMES: Final = {syms.tname, syms.tname_star}
 ASSIGNMENTS: Final = {
@@ -121,6 +122,7 @@
     ">>=",
     "**=",
     "//=",
+    ":",
 }
 
 IMPLICIT_TUPLE: Final = {syms.testlist, syms.testlist_star_expr, syms.exprlist}
@@ -346,9 +348,7 @@ def whitespace(leaf: Leaf, *, complex_subscript: bool, mode: Mode) -> str:  # no
 
             return NO
 
-        elif Preview.walrus_subscript in mode and (
-            t == token.COLONEQUAL or prev.type == token.COLONEQUAL
-        ):
+        elif t == token.COLONEQUAL or prev.type == token.COLONEQUAL:
             return SPACE
 
         elif not complex_subscript:
@@ -753,13 +753,9 @@ def is_function_or_class(node: Node) -> bool:
     return node.type in {syms.funcdef, syms.classdef, syms.async_funcdef}
 
 
-def is_stub_suite(node: Node, mode: Mode) -> bool:
+def is_stub_suite(node: Node) -> bool:
     """Return True if `node` is a suite with a stub body."""
-    if (
-        node.parent is not None
-        and Preview.dummy_implementations in mode
-        and not is_parent_function_or_class(node)
-    ):
+    if node.parent is not None and not is_parent_function_or_class(node):
         return False
 
     # If there is a comment, we want to keep it.
diff --git a/tests/data/cases/preview_allow_empty_first_line.py b/tests/data/cases/allow_empty_first_line.py
similarity index 98%
rename from tests/data/cases/preview_allow_empty_first_line.py
rename to tests/data/cases/allow_empty_first_line.py
index 4269987305d..32a170a97d0 100644
--- a/tests/data/cases/preview_allow_empty_first_line.py
+++ b/tests/data/cases/allow_empty_first_line.py
@@ -1,4 +1,3 @@
-# flags: --preview
 def foo():
     """
     Docstring
diff --git a/tests/data/cases/preview_async_stmts.py b/tests/data/cases/async_stmts.py
similarity index 93%
rename from tests/data/cases/preview_async_stmts.py
rename to tests/data/cases/async_stmts.py
index 0a7671be5a6..fe9594b2164 100644
--- a/tests/data/cases/preview_async_stmts.py
+++ b/tests/data/cases/async_stmts.py
@@ -1,4 +1,3 @@
-# flags: --preview
 async def func() -> (int):
     return 0
 
diff --git a/tests/data/cases/comments5.py b/tests/data/cases/comments5.py
index bda40619f62..4270d3a09a2 100644
--- a/tests/data/cases/comments5.py
+++ b/tests/data/cases/comments5.py
@@ -45,8 +45,7 @@ def wat():
 @deco2(with_args=True)
 # leading 3
 @deco3
-def decorated1():
-    ...
+def decorated1(): ...
 
 
 # leading 1
@@ -54,8 +53,7 @@ def decorated1():
 # leading 2
 @deco2(with_args=True)
 # leading function comment
-def decorated1():
-    ...
+def decorated1(): ...
 
 
 # Note: this is fixed in
@@ -65,8 +63,7 @@ def decorated1():
 
 
 # This comment should be split from `some_instruction` by two lines but isn't.
-def g():
-    ...
+def g(): ...
 
 
 if __name__ == "__main__":
diff --git a/tests/data/cases/conditional_expression.py b/tests/data/cases/conditional_expression.py
index 76251bd9318..f65d6fb00e7 100644
--- a/tests/data/cases/conditional_expression.py
+++ b/tests/data/cases/conditional_expression.py
@@ -1,4 +1,3 @@
-# flags: --preview
 long_kwargs_single_line = my_function(
     foo="test, this is a sample value",
     bar=some_long_value_name_foo_bar_baz if some_boolean_variable else some_fallback_value_foo_bar_baz,
@@ -197,7 +196,9 @@ def foo(wait: bool = True):
     time.sleep(1) if wait else None
 
 
-a = "".join((
-    "",  # comment
-    "" if True else "",
-))
+a = "".join(
+    (
+        "",  # comment
+        "" if True else "",
+    )
+)
diff --git a/tests/data/cases/preview_context_managers_38.py b/tests/data/cases/context_managers_38.py
similarity index 96%
rename from tests/data/cases/preview_context_managers_38.py
rename to tests/data/cases/context_managers_38.py
index 719d94fdcc5..54fb97c708b 100644
--- a/tests/data/cases/preview_context_managers_38.py
+++ b/tests/data/cases/context_managers_38.py
@@ -1,4 +1,4 @@
-# flags: --preview --minimum-version=3.8
+# flags: --minimum-version=3.8
 with \
      make_context_manager1() as cm1, \
      make_context_manager2() as cm2, \
diff --git a/tests/data/cases/preview_context_managers_39.py b/tests/data/cases/context_managers_39.py
similarity index 98%
rename from tests/data/cases/preview_context_managers_39.py
rename to tests/data/cases/context_managers_39.py
index 589e00ad187..60fd1a56409 100644
--- a/tests/data/cases/preview_context_managers_39.py
+++ b/tests/data/cases/context_managers_39.py
@@ -1,4 +1,4 @@
-# flags: --preview --minimum-version=3.9
+# flags: --minimum-version=3.9
 with \
      make_context_manager1() as cm1, \
      make_context_manager2() as cm2, \
diff --git a/tests/data/cases/preview_context_managers_autodetect_310.py b/tests/data/cases/context_managers_autodetect_310.py
similarity index 93%
rename from tests/data/cases/preview_context_managers_autodetect_310.py
rename to tests/data/cases/context_managers_autodetect_310.py
index a9e31076f03..80f211032e5 100644
--- a/tests/data/cases/preview_context_managers_autodetect_310.py
+++ b/tests/data/cases/context_managers_autodetect_310.py
@@ -1,4 +1,4 @@
-# flags: --preview --minimum-version=3.10
+# flags: --minimum-version=3.10
 # This file uses pattern matching introduced in Python 3.10.
 
 
diff --git a/tests/data/cases/preview_context_managers_autodetect_311.py b/tests/data/cases/context_managers_autodetect_311.py
similarity index 92%
rename from tests/data/cases/preview_context_managers_autodetect_311.py
rename to tests/data/cases/context_managers_autodetect_311.py
index af1e83fe74c..020c4cea967 100644
--- a/tests/data/cases/preview_context_managers_autodetect_311.py
+++ b/tests/data/cases/context_managers_autodetect_311.py
@@ -1,4 +1,4 @@
-# flags: --preview --minimum-version=3.11
+# flags: --minimum-version=3.11
 # This file uses except* clause in Python 3.11.
 
 
diff --git a/tests/data/cases/preview_context_managers_autodetect_38.py b/tests/data/cases/context_managers_autodetect_38.py
similarity index 98%
rename from tests/data/cases/preview_context_managers_autodetect_38.py
rename to tests/data/cases/context_managers_autodetect_38.py
index 25217a40604..79e438b995e 100644
--- a/tests/data/cases/preview_context_managers_autodetect_38.py
+++ b/tests/data/cases/context_managers_autodetect_38.py
@@ -1,4 +1,3 @@
-# flags: --preview
 # This file doesn't use any Python 3.9+ only grammars.
 
 
diff --git a/tests/data/cases/preview_context_managers_autodetect_39.py b/tests/data/cases/context_managers_autodetect_39.py
similarity index 93%
rename from tests/data/cases/preview_context_managers_autodetect_39.py
rename to tests/data/cases/context_managers_autodetect_39.py
index 3f72e48db9d..98e674b2f9d 100644
--- a/tests/data/cases/preview_context_managers_autodetect_39.py
+++ b/tests/data/cases/context_managers_autodetect_39.py
@@ -1,4 +1,4 @@
-# flags: --preview --minimum-version=3.9
+# flags: --minimum-version=3.9
 # This file uses parenthesized context managers introduced in Python 3.9.
 
 
diff --git a/tests/data/cases/preview_dummy_implementations.py b/tests/data/cases/dummy_implementations.py
similarity index 99%
rename from tests/data/cases/preview_dummy_implementations.py
rename to tests/data/cases/dummy_implementations.py
index 3cd392c9587..0a52c081bcc 100644
--- a/tests/data/cases/preview_dummy_implementations.py
+++ b/tests/data/cases/dummy_implementations.py
@@ -1,4 +1,3 @@
-# flags: --preview
 from typing import NoReturn, Protocol, Union, overload
 
 class Empty:
diff --git a/tests/data/cases/empty_lines.py b/tests/data/cases/empty_lines.py
index 4fd47b93dca..4c03e432383 100644
--- a/tests/data/cases/empty_lines.py
+++ b/tests/data/cases/empty_lines.py
@@ -119,6 +119,7 @@ def f():
     if not prev:
         prevp = preceding_leaf(p)
         if not prevp or prevp.type in OPENING_BRACKETS:
+
             return NO
 
         if prevp.type == token.EQUAL:
diff --git a/tests/data/cases/fmtonoff.py b/tests/data/cases/fmtonoff.py
index d1f15cd5c8b..8af94563af8 100644
--- a/tests/data/cases/fmtonoff.py
+++ b/tests/data/cases/fmtonoff.py
@@ -243,12 +243,8 @@ def spaces_types(
     g: int = 1 if False else 2,
     h: str = "",
     i: str = r"",
-):
-    ...
-
-
-def spaces2(result=_core.Value(None)):
-    ...
+): ...
+def spaces2(result=_core.Value(None)): ...
 
 
 something = {
diff --git a/tests/data/cases/fmtonoff5.py b/tests/data/cases/fmtonoff5.py
index 181151b6bd6..4c134a9eea3 100644
--- a/tests/data/cases/fmtonoff5.py
+++ b/tests/data/cases/fmtonoff5.py
@@ -161,8 +161,7 @@ def  this_wont_be_formatted ( self ) -> str: ...
 
 
 class Factory(t.Protocol):
-    def this_will_be_formatted(self, **kwargs) -> Named:
-        ...
+    def this_will_be_formatted(self, **kwargs) -> Named: ...
 
     # fmt: on
 
diff --git a/tests/data/cases/preview_form_feeds.py b/tests/data/cases/form_feeds.py
similarity index 99%
rename from tests/data/cases/preview_form_feeds.py
rename to tests/data/cases/form_feeds.py
index dc3bd6cfe2e..48ffc98106b 100644
--- a/tests/data/cases/preview_form_feeds.py
+++ b/tests/data/cases/form_feeds.py
@@ -1,4 +1,3 @@
-# flags: --preview
 
 
 # Warning! This file contains form feeds (ASCII 0x0C, often represented by \f or ^L).
diff --git a/tests/data/cases/function.py b/tests/data/cases/function.py
index 2d642c8731b..4e3f91fd8b1 100644
--- a/tests/data/cases/function.py
+++ b/tests/data/cases/function.py
@@ -158,10 +158,7 @@ def spaces_types(
     g: int = 1 if False else 2,
     h: str = "",
     i: str = r"",
-):
-    ...
-
-
+): ...
 def spaces2(result=_core.Value(None)):
     assert fut is self._read_fut, (fut, self._read_fut)
 
diff --git a/tests/data/cases/remove_newline_after_match.py b/tests/data/cases/keep_newline_after_match.py
similarity index 93%
rename from tests/data/cases/remove_newline_after_match.py
rename to tests/data/cases/keep_newline_after_match.py
index fe6592b664d..dbeccce6264 100644
--- a/tests/data/cases/remove_newline_after_match.py
+++ b/tests/data/cases/keep_newline_after_match.py
@@ -21,15 +21,21 @@ def http_status(status):
 
 # output
 def http_status(status):
+
     match status:
+
         case 400:
+
             return "Bad request"
 
         case 401:
+
             return "Unauthorized"
 
         case 403:
+
             return "Forbidden"
 
         case 404:
+
             return "Not found"
\ No newline at end of file
diff --git a/tests/data/cases/long_strings_flag_disabled.py b/tests/data/cases/long_strings_flag_disabled.py
index db3954e3abd..d81c331cab2 100644
--- a/tests/data/cases/long_strings_flag_disabled.py
+++ b/tests/data/cases/long_strings_flag_disabled.py
@@ -43,8 +43,10 @@
     % (
         "formatted",
         "string",
-    ): "This is a really really really long string that has to go inside of a dictionary. It is %s bad (#%d)."
-    % ("soooo", 2),
+    ): (
+        "This is a really really really long string that has to go inside of a dictionary. It is %s bad (#%d)."
+        % ("soooo", 2)
+    ),
 }
 
 func_with_keywords(
@@ -254,10 +256,12 @@
     + CONCATENATED
     + "using the '+' operator."
 )
-annotated_variable: Final = "This is a large string that has a type annotation attached to it. A type annotation should NOT stop a long string from being wrapped."
-annotated_variable: Literal[
-    "fakse_literal"
-] = "This is a large string that has a type annotation attached to it. A type annotation should NOT stop a long string from being wrapped."
+annotated_variable: Final = (
+    "This is a large string that has a type annotation attached to it. A type annotation should NOT stop a long string from being wrapped."
+)
+annotated_variable: Literal["fakse_literal"] = (
+    "This is a large string that has a type annotation attached to it. A type annotation should NOT stop a long string from being wrapped."
+)
 
 backslashes = "This is a really long string with \"embedded\" double quotes and 'single' quotes that also handles checking for an even number of backslashes \\"
 backslashes = "This is a really long string with \"embedded\" double quotes and 'single' quotes that also handles checking for an even number of backslashes \\\\"
diff --git a/tests/data/cases/module_docstring_1.py b/tests/data/cases/module_docstring_1.py
index d5897b4db60..5751154f7f0 100644
--- a/tests/data/cases/module_docstring_1.py
+++ b/tests/data/cases/module_docstring_1.py
@@ -1,4 +1,3 @@
-# flags: --preview
 """Single line module-level docstring should be followed by single newline."""
 
 
diff --git a/tests/data/cases/module_docstring_2.py b/tests/data/cases/module_docstring_2.py
index 1cc9aea9aea..ac486096c02 100644
--- a/tests/data/cases/module_docstring_2.py
+++ b/tests/data/cases/module_docstring_2.py
@@ -1,7 +1,7 @@
 # flags: --preview
 """I am a very helpful module docstring.
 
-With trailing spaces:      
+With trailing spaces (only removed with unify_docstring_detection on):      
 Lorem ipsum dolor sit amet, consectetur adipiscing elit,
 sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
 Ut enim ad minim veniam,
@@ -39,7 +39,7 @@
 # output
 """I am a very helpful module docstring.
 
-With trailing spaces:
+With trailing spaces (only removed with unify_docstring_detection on):
 Lorem ipsum dolor sit amet, consectetur adipiscing elit,
 sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
 Ut enim ad minim veniam,
diff --git a/tests/data/cases/module_docstring_3.py b/tests/data/cases/module_docstring_3.py
index 0631e136a3d..3d0058dd554 100644
--- a/tests/data/cases/module_docstring_3.py
+++ b/tests/data/cases/module_docstring_3.py
@@ -1,4 +1,3 @@
-# flags: --preview
 """Single line module-level docstring should be followed by single newline."""
 a = 1
 
diff --git a/tests/data/cases/module_docstring_4.py b/tests/data/cases/module_docstring_4.py
index 515174dcc04..b1720078f71 100644
--- a/tests/data/cases/module_docstring_4.py
+++ b/tests/data/cases/module_docstring_4.py
@@ -1,4 +1,3 @@
-# flags: --preview
 """Single line module-level docstring should be followed by single newline."""
 
 a = 1
diff --git a/tests/data/cases/module_docstring_followed_by_class.py b/tests/data/cases/module_docstring_followed_by_class.py
index 6fdbfc8c240..c291e61b960 100644
--- a/tests/data/cases/module_docstring_followed_by_class.py
+++ b/tests/data/cases/module_docstring_followed_by_class.py
@@ -1,4 +1,3 @@
-# flags: --preview
 """Two blank lines between module docstring and a class."""
 class MyClass:
     pass
diff --git a/tests/data/cases/module_docstring_followed_by_function.py b/tests/data/cases/module_docstring_followed_by_function.py
index 5913a59e1fe..fd29b98da8e 100644
--- a/tests/data/cases/module_docstring_followed_by_function.py
+++ b/tests/data/cases/module_docstring_followed_by_function.py
@@ -1,4 +1,3 @@
-# flags: --preview
 """Two blank lines between module docstring and a function def."""
 def function():
     pass
diff --git a/tests/data/cases/nested_stub.py b/tests/data/cases/nested_stub.py
index ef13c588ce6..40ca11e9330 100644
--- a/tests/data/cases/nested_stub.py
+++ b/tests/data/cases/nested_stub.py
@@ -1,4 +1,4 @@
-# flags: --pyi --preview
+# flags: --pyi
 import sys
 
 class Outer:
diff --git a/tests/data/cases/preview_no_blank_line_before_docstring.py b/tests/data/cases/no_blank_line_before_docstring.py
similarity index 98%
rename from tests/data/cases/preview_no_blank_line_before_docstring.py
rename to tests/data/cases/no_blank_line_before_docstring.py
index faeaa1e46e4..ced125fef78 100644
--- a/tests/data/cases/preview_no_blank_line_before_docstring.py
+++ b/tests/data/cases/no_blank_line_before_docstring.py
@@ -1,4 +1,3 @@
-# flags: --preview
 def line_before_docstring():
 
     """Please move me up"""
@@ -63,4 +62,5 @@ class MultilineDocstringsAsWell:
 
 
 class SingleQuotedDocstring:
+
     "I'm a docstring but I don't even get triple quotes."
diff --git a/tests/data/cases/preview_pattern_matching_long.py b/tests/data/cases/pattern_matching_long.py
similarity index 94%
rename from tests/data/cases/preview_pattern_matching_long.py
rename to tests/data/cases/pattern_matching_long.py
index df849fdc4f2..9a944c9d0c9 100644
--- a/tests/data/cases/preview_pattern_matching_long.py
+++ b/tests/data/cases/pattern_matching_long.py
@@ -1,4 +1,4 @@
-# flags: --preview --minimum-version=3.10
+# flags: --minimum-version=3.10
 match x:
     case "abcd" | "abcd" | "abcd" :
         pass
diff --git a/tests/data/cases/preview_pattern_matching_trailing_comma.py b/tests/data/cases/pattern_matching_trailing_comma.py
similarity index 90%
rename from tests/data/cases/preview_pattern_matching_trailing_comma.py
rename to tests/data/cases/pattern_matching_trailing_comma.py
index e6c0d88bb80..5660b0f6a14 100644
--- a/tests/data/cases/preview_pattern_matching_trailing_comma.py
+++ b/tests/data/cases/pattern_matching_trailing_comma.py
@@ -1,4 +1,4 @@
-# flags: --preview --minimum-version=3.10
+# flags: --minimum-version=3.10
 match maybe, multiple:
     case perhaps, 5:
         pass
diff --git a/tests/data/cases/pep604_union_types_line_breaks.py b/tests/data/cases/pep604_union_types_line_breaks.py
index fee2b840494..745bc9e8b02 100644
--- a/tests/data/cases/pep604_union_types_line_breaks.py
+++ b/tests/data/cases/pep604_union_types_line_breaks.py
@@ -1,4 +1,4 @@
-# flags: --preview --minimum-version=3.10
+# flags: --minimum-version=3.10
 # This has always worked
 z= Loooooooooooooooooooooooong | Loooooooooooooooooooooooong | Loooooooooooooooooooooooong | Loooooooooooooooooooooooong
 
diff --git a/tests/data/cases/pep_572_py310.py b/tests/data/cases/pep_572_py310.py
index 9f999deeb89..ba488d4741c 100644
--- a/tests/data/cases/pep_572_py310.py
+++ b/tests/data/cases/pep_572_py310.py
@@ -1,8 +1,8 @@
 # flags: --minimum-version=3.10
 # Unparenthesized walruses are now allowed in indices since Python 3.10.
-x[a:=0]
-x[a:=0, b:=1]
-x[5, b:=0]
+x[a := 0]
+x[a := 0, b := 1]
+x[5, b := 0]
 
 # Walruses are allowed inside generator expressions on function calls since 3.10.
 if any(match := pattern_error.match(s) for s in buffer):
diff --git a/tests/data/cases/pep_572_remove_parens.py b/tests/data/cases/pep_572_remove_parens.py
index 24f1ac29168..f0026ceb032 100644
--- a/tests/data/cases/pep_572_remove_parens.py
+++ b/tests/data/cases/pep_572_remove_parens.py
@@ -96,18 +96,16 @@ async def await_the_walrus():
 foo(x=(y := f(x)))
 
 
-def foo(answer=(p := 42)):
-    ...
+def foo(answer=(p := 42)): ...
 
 
-def foo2(answer: (p := 42) = 5):
-    ...
+def foo2(answer: (p := 42) = 5): ...
 
 
 lambda: (x := 1)
 
 a[(x := 12)]
-a[:(x := 13)]
+a[: (x := 13)]
 
 # we don't touch expressions in f-strings but if we do one day, don't break 'em
 f"{(x:=10)}"
diff --git a/tests/data/cases/preview_pep_572.py b/tests/data/cases/pep_572_slices.py
similarity index 75%
rename from tests/data/cases/preview_pep_572.py
rename to tests/data/cases/pep_572_slices.py
index 75ad0cc4176..aa772b1f1f5 100644
--- a/tests/data/cases/preview_pep_572.py
+++ b/tests/data/cases/pep_572_slices.py
@@ -1,4 +1,3 @@
-# flags: --preview
 x[(a:=0):]
 x[:(a:=0)]
 
diff --git a/tests/data/cases/preview_percent_precedence.py b/tests/data/cases/percent_precedence.py
similarity index 91%
rename from tests/data/cases/preview_percent_precedence.py
rename to tests/data/cases/percent_precedence.py
index aeaf450ff5e..7822e42c69d 100644
--- a/tests/data/cases/preview_percent_precedence.py
+++ b/tests/data/cases/percent_precedence.py
@@ -1,4 +1,3 @@
-# flags: --preview
 ("" % a) ** 2
 ("" % a)[0]
 ("" % a)()
@@ -31,9 +30,9 @@
 2 // ("" % a)
 2 % ("" % a)
 +("" % a)
-b + "" % a
+b + ("" % a)
 -("" % a)
-b - "" % a
+b - ("" % a)
 b + -("" % a)
 ~("" % a)
 2 ** ("" % a)
diff --git a/tests/data/cases/preview_power_op_spacing.py b/tests/data/cases/power_op_spacing_long.py
similarity index 99%
rename from tests/data/cases/preview_power_op_spacing.py
rename to tests/data/cases/power_op_spacing_long.py
index 650c6fecb20..30e6eb788b3 100644
--- a/tests/data/cases/preview_power_op_spacing.py
+++ b/tests/data/cases/power_op_spacing_long.py
@@ -1,4 +1,3 @@
-# flags: --preview
 a = 1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1
 b = 1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1**1
 c = 1 ** 1 ** 1 ** 1 ** 1 ** 1 ** 1 ** 1 ** 1 ** 1 ** 1 ** 1 ** 1 ** 1 ** 1 ** 1 ** 1 ** 1 ** 1 ** 1 ** 1 ** 1 ** 1 ** 1 ** 1 ** 1 ** 1 ** 1
diff --git a/tests/data/cases/preview_prefer_rhs_split.py b/tests/data/cases/prefer_rhs_split.py
similarity index 99%
rename from tests/data/cases/preview_prefer_rhs_split.py
rename to tests/data/cases/prefer_rhs_split.py
index 28d89c368c0..f3d9fd67251 100644
--- a/tests/data/cases/preview_prefer_rhs_split.py
+++ b/tests/data/cases/prefer_rhs_split.py
@@ -1,4 +1,3 @@
-# flags: --preview
 first_item, second_item = (
     some_looooooooong_module.some_looooooooooooooong_function_name(
         first_argument, second_argument, third_argument
diff --git a/tests/data/cases/py310_pep572.py b/tests/data/cases/py310_pep572.py
index 172be3898d6..73fbe44d42c 100644
--- a/tests/data/cases/py310_pep572.py
+++ b/tests/data/cases/py310_pep572.py
@@ -1,4 +1,4 @@
-# flags: --preview --minimum-version=3.10
+# flags: --minimum-version=3.10
 x[a:=0]
 x[a := 0]
 x[a := 0, b := 1]
diff --git a/tests/data/cases/python39.py b/tests/data/cases/python39.py
index 1b9536c1529..85eddc38e00 100644
--- a/tests/data/cases/python39.py
+++ b/tests/data/cases/python39.py
@@ -15,19 +15,16 @@ def f():
 # output
 
 @relaxed_decorator[0]
-def f():
-    ...
+def f(): ...
 
 
 @relaxed_decorator[
     extremely_long_name_that_definitely_will_not_fit_on_one_line_of_standard_length
 ]
-def f():
-    ...
+def f(): ...
 
 
 @extremely_long_variable_name_that_doesnt_fit := complex.expression(
     with_long="arguments_value_that_wont_fit_at_the_end_of_the_line"
 )
-def f():
-    ...
\ No newline at end of file
+def f(): ...
\ No newline at end of file
diff --git a/tests/data/cases/raw_docstring.py b/tests/data/cases/raw_docstring.py
index 751fd3201df..7f88bb2de86 100644
--- a/tests/data/cases/raw_docstring.py
+++ b/tests/data/cases/raw_docstring.py
@@ -1,4 +1,4 @@
-# flags: --preview --skip-string-normalization
+# flags: --skip-string-normalization
 class C:
 
     r"""Raw"""
diff --git a/tests/data/cases/preview_docstring_no_string_normalization.py b/tests/data/cases/raw_docstring_no_string_normalization.py
similarity index 88%
rename from tests/data/cases/preview_docstring_no_string_normalization.py
rename to tests/data/cases/raw_docstring_no_string_normalization.py
index 712c7364f51..a201c1e8fae 100644
--- a/tests/data/cases/preview_docstring_no_string_normalization.py
+++ b/tests/data/cases/raw_docstring_no_string_normalization.py
@@ -1,4 +1,4 @@
-# flags: --preview --skip-string-normalization
+# flags: --skip-string-normalization
 def do_not_touch_this_prefix():
     R"""There was a bug where docstring prefixes would be normalized even with -S."""
 
diff --git a/tests/data/cases/remove_newline_after_code_block_open.py b/tests/data/cases/remove_newline_after_code_block_open.py
index ef2e5c2f6f5..6622e8afb7d 100644
--- a/tests/data/cases/remove_newline_after_code_block_open.py
+++ b/tests/data/cases/remove_newline_after_code_block_open.py
@@ -3,14 +3,14 @@
 
 def foo1():
 
-    print("The newline above me should be deleted!")
+    print("The newline above me should be kept!")
 
 
 def foo2():
 
 
 
-    print("All the newlines above me should be deleted!")
+    print("All the newlines above me should be kept!")
 
 
 def foo3():
@@ -30,31 +30,31 @@ def foo4():
 class Foo:
     def bar(self):
 
-        print("The newline above me should be deleted!")
+        print("The newline above me should be kept!")
 
 
 for i in range(5):
 
-    print(f"{i}) The line above me should be removed!")
+    print(f"{i}) The line above me should be kept!")
 
 
 for i in range(5):
 
 
 
-    print(f"{i}) The lines above me should be removed!")
+    print(f"{i}) The lines above me should be kept!")
 
 
 for i in range(5):
 
     for j in range(7):
 
-        print(f"{i}) The lines above me should be removed!")
+        print(f"{i}) The lines above me should be kept!")
 
 
 if random.randint(0, 3) == 0:
 
-    print("The new line above me is about to be removed!")
+    print("The new line above me will be kept!")
 
 
 if random.randint(0, 3) == 0:
@@ -62,43 +62,45 @@ def bar(self):
 
 
 
-    print("The new lines above me is about to be removed!")
+    print("The new lines above me will be kept!")
 
 
 if random.randint(0, 3) == 0:
+
     if random.uniform(0, 1) > 0.5:
-        print("Two lines above me are about to be removed!")
+
+        print("Two lines above me will be kept!")
 
 
 while True:
 
-    print("The newline above me should be deleted!")
+    print("The newline above me should be kept!")
 
 
 while True:
 
 
 
-    print("The newlines above me should be deleted!")
+    print("The newlines above me should be kept!")
 
 
 while True:
 
     while False:
 
-        print("The newlines above me should be deleted!")
+        print("The newlines above me should be kept!")
 
 
 with open("/path/to/file.txt", mode="w") as file:
 
-    file.write("The new line above me is about to be removed!")
+    file.write("The new line above me will be kept!")
 
 
 with open("/path/to/file.txt", mode="w") as file:
 
 
 
-    file.write("The new lines above me is about to be removed!")
+    file.write("The new lines above me will be kept!")
 
 
 with open("/path/to/file.txt", mode="r") as read_file:
@@ -113,20 +115,24 @@ def bar(self):
 
 
 def foo1():
-    print("The newline above me should be deleted!")
+
+    print("The newline above me should be kept!")
 
 
 def foo2():
-    print("All the newlines above me should be deleted!")
+
+    print("All the newlines above me should be kept!")
 
 
 def foo3():
+
     print("No newline above me!")
 
     print("There is a newline above me, and that's OK!")
 
 
 def foo4():
+
     # There is a comment here
 
     print("The newline above me should not be deleted!")
@@ -134,56 +140,73 @@ def foo4():
 
 class Foo:
     def bar(self):
-        print("The newline above me should be deleted!")
+
+        print("The newline above me should be kept!")
 
 
 for i in range(5):
-    print(f"{i}) The line above me should be removed!")
+
+    print(f"{i}) The line above me should be kept!")
 
 
 for i in range(5):
-    print(f"{i}) The lines above me should be removed!")
+
+    print(f"{i}) The lines above me should be kept!")
 
 
 for i in range(5):
+
     for j in range(7):
-        print(f"{i}) The lines above me should be removed!")
+
+        print(f"{i}) The lines above me should be kept!")
 
 
 if random.randint(0, 3) == 0:
-    print("The new line above me is about to be removed!")
+
+    print("The new line above me will be kept!")
 
 
 if random.randint(0, 3) == 0:
-    print("The new lines above me is about to be removed!")
+
+    print("The new lines above me will be kept!")
 
 
 if random.randint(0, 3) == 0:
+
     if random.uniform(0, 1) > 0.5:
-        print("Two lines above me are about to be removed!")
+
+        print("Two lines above me will be kept!")
 
 
 while True:
-    print("The newline above me should be deleted!")
+
+    print("The newline above me should be kept!")
 
 
 while True:
-    print("The newlines above me should be deleted!")
+
+    print("The newlines above me should be kept!")
 
 
 while True:
+
     while False:
-        print("The newlines above me should be deleted!")
+
+        print("The newlines above me should be kept!")
 
 
 with open("/path/to/file.txt", mode="w") as file:
-    file.write("The new line above me is about to be removed!")
+
+    file.write("The new line above me will be kept!")
 
 
 with open("/path/to/file.txt", mode="w") as file:
-    file.write("The new lines above me is about to be removed!")
+
+    file.write("The new lines above me will be kept!")
 
 
 with open("/path/to/file.txt", mode="r") as read_file:
+
     with open("/path/to/output_file.txt", mode="w") as write_file:
+
         write_file.writelines(read_file.readlines())
diff --git a/tests/data/cases/return_annotation_brackets.py b/tests/data/cases/return_annotation_brackets.py
index 8509ecdb92c..ed05bed61f4 100644
--- a/tests/data/cases/return_annotation_brackets.py
+++ b/tests/data/cases/return_annotation_brackets.py
@@ -88,7 +88,6 @@ def foo() -> tuple[int, int, int,]:
     return 2
 
 # Magic trailing comma example, with params
-# this is broken - the trailing comma is transferred to the param list. Fixed in preview
 def foo(a,b) -> tuple[int, int, int,]:
     return 2
 
@@ -194,30 +193,27 @@ def foo() -> tuple[int, int, int]:
     return 2
 
 
-def foo() -> (
-    tuple[
-        loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong,
-        loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong,
-        loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong,
-    ]
-):
+def foo() -> tuple[
+    loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong,
+    loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong,
+    loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong,
+]:
     return 2
 
 
 # Magic trailing comma example
-def foo() -> (
-    tuple[
-        int,
-        int,
-        int,
-    ]
-):
+def foo() -> tuple[
+    int,
+    int,
+    int,
+]:
     return 2
 
 
 # Magic trailing comma example, with params
-# this is broken - the trailing comma is transferred to the param list. Fixed in preview
-def foo(
-    a, b
-) -> tuple[int, int, int,]:
+def foo(a, b) -> tuple[
+    int,
+    int,
+    int,
+]:
     return 2
diff --git a/tests/data/cases/preview_single_line_format_skip_with_multiple_comments.py b/tests/data/cases/single_line_format_skip_with_multiple_comments.py
similarity index 97%
rename from tests/data/cases/preview_single_line_format_skip_with_multiple_comments.py
rename to tests/data/cases/single_line_format_skip_with_multiple_comments.py
index efde662baa8..7212740fc42 100644
--- a/tests/data/cases/preview_single_line_format_skip_with_multiple_comments.py
+++ b/tests/data/cases/single_line_format_skip_with_multiple_comments.py
@@ -1,4 +1,3 @@
-# flags: --preview
 foo =  123  # fmt: skip # noqa: E501 # pylint
 bar =    (
     123   ,
diff --git a/tests/data/cases/preview_trailing_comma.py b/tests/data/cases/trailing_comma.py
similarity index 97%
rename from tests/data/cases/preview_trailing_comma.py
rename to tests/data/cases/trailing_comma.py
index bba7e7ad16d..5b09c664606 100644
--- a/tests/data/cases/preview_trailing_comma.py
+++ b/tests/data/cases/trailing_comma.py
@@ -1,4 +1,3 @@
-# flags: --preview
 e = {
     "a": fun(msg, "ts"),
     "longggggggggggggggid": ...,
diff --git a/tests/data/cases/walrus_in_dict.py b/tests/data/cases/walrus_in_dict.py
index c33eecd84a6..c91ad9e8611 100644
--- a/tests/data/cases/walrus_in_dict.py
+++ b/tests/data/cases/walrus_in_dict.py
@@ -1,7 +1,9 @@
 # flags: --preview
+# This is testing an issue that is specific to the preview style
 {
     "is_update": (up := commit.hash in update_hashes)
 }
 
 # output
+# This is testing an issue that is specific to the preview style
 {"is_update": (up := commit.hash in update_hashes)}