During North American Peak times (evening hours), Excalibur and Hyperion are both restricted from new character creation almost every day. There are also some others that have that condition, but not as often.

If you try in the early morning hours (like maybe around 9:00 am Eastern), you should find that all NA/EU worlds should be open to new character creation. At that hour, the worlds in the JP Data Center will be the ones with no new characters allowed. At that hour, there are usually quite a few more of the JP Data Center worlds locked out of new character creation than will ever happen on the NA/EU worlds.