@lwn "One can even create a room on one server, have a user on another server join, and then have the first server leave the room, passing off the responsibility for operating the room to the new server."
As soon as one account from a server is joining a room, the content of that room is synchronized to the server. No server has a special responsibility in the room. Only accounts can join or leave a room and only accounts have roles (creator, admin, moderator,..) in a room. #Matrix