I hope you won't mind if I double this here.
I understand your reasoning to why you won't make announcements on Discord (separate channel or not). Therefore I propose an alternative:
1) Just create an additional channel for CF-related discussion only. So that questions on the game, server, etc etc, can be tracked there.
2) (optional) Allow Moderators to delete posts to enforce the "no off-topic" rule in said channel.
Also maybe a "Staff Room" channel (mods and higher only), just in case.
I think this would be an easy solution. Hopefully I'm not too demanding.