When are congested worlds "reviewed" to be opened?

[Anger]

If you're referring to the congested status of servers like Balmung that are completely locked from character creation until they lift it, It usually changes on larger patches from what I recall, though who knows how often they review those servers to be opened up again or stay locked.

If you're referring to servers that aren't completely locked and sometimes open randomly for character creation, it's based on the current number of users logged in at the time as far as I'm aware, so it can change and lock down and open up through the day & night depending on activity.

Yes, I am referring to the "Congested" locked servers like Balmung that do not open up at any time unless the lock is lifted.