Notifications on Announcements
An announcement in a channel doesn't notify the channel members unless you @Mention them. This should surely be automatic when an announcement is posted.
K. Kieffer commented
This depends on how the person has their notifications set up. One can opt to receive notifications for all new posts in the banner and feed, in only the feed, or not at all. I have mine set to not at all since I have so many Teams due to distance learning.
Mike Williams commented
It's also very important for when you're crossposting channels/teams otherwise you find yourself having to @mention possibly dozens of team or channel names.
Yuri Banens commented
Also if/when posting an announcement across multiple teams.