My expectation would be that they hire in batches. First batches do the academy and everything, then get sent on a temporary duty to train on the EWR sector while it's at N90. They would have a hard set date out of N90 when EWR leaves. They would be used at staffing when it moves to PHL. This gives you some staffing to help run the sector, you then move the sector with the new staffing, the vets that want to leave, and temporary duty some of the ones that want to stay to help train controllers at PHL.
I think everyone that applied knows this is to staff the EWR sector.