Just let me say I'm happy I was able to create my character on Moogle in Phase 4. Took what, only 8 hours of updating the server list before I was able to slip in. Later most of the servers were locked from new character creation altogether.

When SE announces beforehand that they might face congestion and need to restrict server usage, you'll know what to expect

Hopefully they have been able to expand their servers, though probably not.