Stalagg created August 14 - 12 days before servers went live.
I haven’t found the post that said Stalagg was full but I am pretty sure it was before the 26th.
The creation of more servers supports that it indeed was full on that date and that you were told to move off again.
At this time, all realms that have a Full or High population tag are expected to experience extended queues. We urge players on realms marked Full or High to plan to play on one of these new realms to avoid the longest queues, and to help spread the player population as evenly as possible and provide the best play experience for everyone.