Oops, Sorry~I haven’t even found the notification settings myself till then
It seems everyone gets notified of official news & announcements by default.
But you can manually change that – go to your profile → Preferences → Tracking → Muted, and add the topics or categories you want to silence.
Hey, I just tweaked the default notification settings a little bit: Previously, every post and reply in “News and Announcements” sent a notification. Now only the first post of each topic will – no more reply notifications.
PS: You can also change your own notification settings under Profile > Preferences.