If a few people are on one server and all they're friends can't get on (if they have free one-time transfers) then its highly likely the people who are on the server will be willing to transfer to a low population server so that they're friends can join them. There will still be a little bit of login issues, since the MMO has still just launched, but it won't be nearly as bad. When the game calms down those issues should be gone altogether.