In this post you are somehow implicitly referring to usage of Projucer.
The fact is, that some of us don’t use it at all, or use it only to bootstrap projects. In consideration of that, I’d say that Projucer would be an insufficient advertiser of those changes anyway.
In my opinion, it is always better to introduce breaking changes in a way that requires developer action when the offending commit is merged in/cherry picked, and surround the corresponding area of code with a clear comment about what has happened.
Also, such breaking changes should be properly advertised here on the forum too (which has been done pretty well in the past) and a link to the corresponding topic should be added to the existing topic that lists breaking changes (I’m going to search it and edit this post with the link later).
EDIT: here is that topic (didn’t remember it was this old and this ‘stale’): List of changes that impact user-code (since 1.52 release)