As was discussed before the migration, we should make more use of the announcement channel.
Obviously core releases already go there. I’m also happy for any plugin maintainers to announce new plugin releases there. If you have an announcement to make and don’t have the rights to post, contact me (or another admin) and I can sort it for you.
Two other thoughts - should we post newsletters and/or other blog posts to that category? My feeling is yes for newsletters, maybe not other posts. Secondly, should I try to hook up that category to auto-post announcements to Twitter, or is that a bit spammy?