Probably me not understanding how it works, but most lemmy.ml communities I subscribed to have this "subscribe pending" but I can still interact with them, just like you did with this thread. So I guess it's just a display issue and we are actually subscribed to those communities?
It's not that your request is awaiting moderation, it's just a server issue. Click on it again until it says subscribe and try again. If it stays at pending, just abort and try another day.