When are congested worlds "reviewed" to be opened?

[Anger]

The only time they would unlock a Congested server like Balmung would be during a scheduled maintenance - the last two times it opened up was during a major patch maintenance (the first time they closed it after 2 weeks because people flooded back to it, and the second time it was unlocked for at least a month or so - longer than the first time). It was a good several months between each time; significant enough for the active population to drop a fair bit.

How often they monitor the total population on Congested worlds is unknown, but I would assume they at least check it once a month (it could be more or less though). The Locked to Character Creation worlds seem to be evaluated every ~6 hours roughly, and open/lock based on the amount of people logged in at the time.

As for when Balmung will open again, with a new expansion coming, if they don't open it before 5.0 drops, it will definitely be a while after it launches before they think about unlocking the server. Simply because everyone is going to be logging in doing main expansion things. With the Aether/Crystal split, it may occur sooner than we'd expect though. It all depends.

Thank you for your informative response, HyoMinPark.