Ironically, since these waves are filling up the current list of servers, it seems clear that later waves will get some additional servers... which will ultimately lead to those that get in last being able to choose servers which may not always be full, unlike those who get in relatively early.
It also means that, if you want to pick a server now for your buddies (and don't have a premade guild), that the server you pick today may be totally full by the time they eventually are allowed in, so you'll end up levelling your guy and they'll probably just choose a different server, since the one you chose is now full...