Update the Media 4 deprecation page (sass#685)

Closes sass#655

source/documentation/breaking-changes/media-logic.md.erb

@@ -1,13 +1,15 @@
 ---
 title: "Breaking Change: Media Queries Level 4"
 introduction: >
-  Sass is adding support for the CSS Media Queries Level 4 specification, but
-  this conflicts with some Sass-specific syntax. That syntax is deprecated to
-  ensure that Sass remains fully CSS-compatible.
+  Sass has added support for the CSS Media Queries Level 4 specification. This
+  originally conflicted with some Sass-specific syntax, so this syntax was
+  deprecated and is now interpreted according to the CSS standard.
 ---
 
+<% impl_status dart: '1.56.0', libsass: false, ruby: false %>
+
 Because Sass supports almost any Sass expression in parenthesized media
-conditions, there are a few constructs that could be broken by adding full
+conditions, there were a few constructs whose meaning was changed by adding full
 support for Media Queries Level 4. Specifically:
 
 * `@media (not (foo))` was historically interpreted by Sass as meaning
@@ -17,16 +19,12 @@ support for Media Queries Level 4. Specifically:
   interpreted as SassScript's logical operators, compiling to `@media (bar)` and
   `@media (foo)` respectively.
 
-Fortunately, these are unlikely to come up in practice.
+Fortunately, these came up very infrequently in practice.
 
 ## Transition Period
 
 <% impl_status dart: '1.54.0', libsass: false, ruby: false %>
 
-First, we'll emit deprecation warnings for the previous ambiguous cases. These
+First, we emitted deprecation warnings for the previous ambiguous cases. These
 will have suggestions for how to preserve the existing behavior or how to use
 the new CSS syntax.
-
-Once the deprecation warnings have been out for at least three months, we'll
-release a version that exclusively interprets these ambiguous cases according to
-the CSS spec.