When the new wards are released for Ishgard, the servers will go down for maintenance for 24 hours, that is long enough so that when the servers come online all first come first serve plots will have run out of hidden timer, making them purchasable immediately.
As of right now it is speculated that of the 26 wards released, 19 will be FC only, 5 will be lottery only and 2 will be FCFS