Amazon is blocking New World players from creating new characters on full servers as it continues to struggle with the MMO's explosive popularity. Now, when a server is full it will be greyed out, with a note to say character creation is not possible.
Of course, if you've already created a character on a full server, you can log in (or, queue to log in, anyway) and play with them as normal.
Amazon signalled the new system last night as it launched a server status page on its website. At the time of this article's publication, many of the servers are marked as full.