Yeah it's there "This house is full, please go to another one.." but unless you know what's up. That could be a huge deterrent to new users which I don't think it's the goal. I now know how this fediverse thing works and that it doesn't really matter which instance I'm using. But for a lot of new users that concept doesn't even register. So it needs to be more transparent from a UX perspective. Sure we could leave it as a sort of "gatekeep" and from a certain point of view it makes sense. It all depends on what the lemmy devs what to achieve.