To support decentralization and spread, should lemmy.world close registration at some point to prevent a performance overload due to too many users? Of course, if registration is disabled, there could be a hint placed somewhere near that from other instances you can interact with content on lemmy.world just like you had registered on it. There could be a link to join-lemmys instance overview.
I think Beehaw defederating was a good thing. Their rules are pretty totalitarian. It would have happened eventually anyway, better to do it sooner to effect the least amount of content I get.