I would probably call them ‘boards’. Communities is too long of a word imo and it makes it sound like the people subscribed all have some kind of shared culture or relationship. That definitely happens in some cases (there are subreddits which have built a community around them) but it’s not universal.
She’s painful to listen to. Can’t string a clear sentence together and laughs constantly. Not inspiring or particularly incisive. Which is a particularly disappointing combo when Biden is the same.