My expectation is that they'll leave them FC-only for a number of lottery rounds to ensure that as many FC's that want a house gets one.

I believe that they are aware that there are desirable locations and that not every FC can afford to place multiple bids. A loss or two might be enough to convince them that a S is "good enough". Once the volume of bids drops below a certain threshold or enough time has passed I'm reasonably confident the FC-only restriction will be lifted.

They really do need to figure out how to deal with the people who took over entire wards. That might be the real reason for the delay.