This used to be the topic for these announcements, but it always went out of sync. The best way to keep up with deprecations is to look at UPGRADING.md once in a while. Mind you, we are adding warnings whenever possible, in which case you get a compile-time warning if you use a deprecated interface, and have Kaleidoscope updated.
Sadly, for some interfaces this wasn’t possible, and the only way to know about them would’ve been UPGRADING.md. We’ve learned the lesson, and most - if not all - new interfaces we add, are added in a way that allows us to add a compile-time deprecation notice if it turns out to be necessary.
If it helps, I can bump the thread mentioned above when we deprecate things in the future - I wouldn’t list the deprecation itself, just post a note to check UPGRADING.md. Bumping is considerably easier than keeping it up-to-date with details, so this process could work better.