When a renaming license is attached to a character, a character name change is mandatory upon login. However, in order to prevent servers outages, there is a certain timing within which character names cannot be updated while servers are experiencing heavy load.
Since the start of Endwalker early access, servers have almost continuously been burdened with congestion due to heavy access. Due to this, it is feared there will be longer spans of time during which character name changes cannot occur, and therefore we are temporarily suspending the Character Renaming Service.

We will notify you again once a reopening date of the service has been determined.

We apologize for any inconvenience this may cause, and we thank you for your understanding and cooperation.