Character creation restrictions are turned on and off periodically throughout the day and it's based on the number of people that are logged on at the time. Since it's the middle of the day on Sunday there's a lot of people on.

Just have him try again later at night or in the morning but he might be able to brute force it.

Anyways on Hyperion I don't receive too many RMT tells, personally. Maybe 2 an hour? It seems to come and go but I don't get outright flooded or anything.