Maybe there should be temporary worlds?

So, everyone points out, quite reasonably, that you're never gonna have the same population a month in that you do at launch. Add more worlds => worlds become empty.

So. Why not just recognize that and work with it? Make temporary worlds. Temporary worlds get some kind of incentive to pick them, but they are guaranteed to be shut down within, say, two months. But with free transfers off them to wherever you want to go.

New players who don't have a specific world they have to be on to play with friends can go to the temporary worlds, play there, have fun, and then join friends on the other worlds when things die down a bit. Everyone gets to log in. No one has to worry about whether their world will still have population post-launch.