New Compatibility Notice

Author: Kordyjan

blog/_posts/2021-10-19-scala-3.1.0-released.md

@@ -10,11 +10,14 @@ Hello from the Scala 3 team! It has already been six weeks since we have announc
 
 This is a first *minor* release after the initial release of Scala 3.0. This has following consequences:
 
-- Scala 3.1 is backward source compatible: any code that was working in 3.0 will also work in 3.1.
 - Scala 3.1 is backward binary compatible: you can use dependencies compiled with Scala 3.0 in 3.1 projects.
 - Scala 3.1 is _not_ forward binary compatible: you _cannot_ use dependencies compiled with Scala 3.1 in Scala 3.0 projects.
 - Updating Scala to 3.1 is not a forward compatible change. If you are a library maintainer and are following SemVer you may want to update in your next minor release.
 
+Although we cannot guarantee full source compatibility between minor versions, we have put a lot of effort into assuring that all code that was working in 3.0.2, except some rare cases, will also work in 3.1.0. This means that if you are an application developer, you can confidently update the compiler version to take advantage of the newest improvements.
+
+If you are a library maintainer, updating to 3.1.0 will force all of your users to need to update as well.  You may consider still publishing your library using 3.0.2 to ensure that users who are reluctant to update a compiler can still use it. On the other hand, we still encourage you to test your library using 3.1.0. We understand that the current state of binary compatibility may be unsatisfactory for library maintainers. We are actively working on improvements in this area in future releases on scala.
+
 ## What's new in 3.1
 
 ### New experimental feature: safer exceptions