Ok, I misunderstood. I thought you were saying everybody was in the game that was going to join and you were just waiting on empires to be uploaded.
Yes there is a problem with PBW whereby once the max number is reached you can't increase it without kicking a person and having them rejoin. In that case you could simply assign GT or whoever you are waiting on fill to the open spots and then if they decide before the game starts not to play boot them and change the max number down.
Or you can just keep kicking people that don't read the game description thourogly.
Geoschmo