Blizzard added a new feature that will be helpful to control overpopulation and server lag. Hopefully, it will also prevent Queues from happening so often.
We’ve implemented a new system that will disable character creation when a realm has a queue to better control realm populations. This system will disable character creation for accounts without characters on an individual realm when it has a queue. This will limit population growth on congested realms during peak hours and assist us in our efforts to provide a better overall gameplay experience for our players, especially those on high population realms.
Please note that players with existing characters on a queued realm will still be able to create characters, and during off hours when there is not a queue all players may create characters as normal.