Hi there!
All news & announcements for any in-game additions would be included with the release notes. Those go into #community:news-and-announcements
You can click on the “bell” to be notified of any announcements in that category and if want to restrict the notifications only to release notes, put a watch on this tag: #patch-notes
The Feedback Snapshot will also list some estimated timelines. This is also in the #community:news-and-announcements category and you can put a watch that with the #dev-update tag.