Weird, it doesn’t work for me for some reason, I have to manually go into the “subscribed” tab each time. Also my point about not being able to subscribe to entire instances still stands. For instance(heh) bookwormstory.social is an instance dedicated to discussing a specific book series and currently has like 5 communities, and I’d have no way of knowing when they started a new community unless I manually checked.
From Library of Ruina. The song “And Then Is Heard No More” from the OST touches on similar themes, go look up the lyrics if you’re intrigued