After talking to a few more people here on the island, it appears as if the last couple comments are pretty much on point.
What they are trying to avoid, is congestion around the luggage/baggage claim area, which can’t handle that many people at once, and would not have all the luggage from the arriving flights. So they are trying to reduce the lines outside by sending those directly through immigration who do not have baggage to claim.
That would be an explanation. It would be preferable to have arrival staff to explain that to the arriving passengers.

Drphilsxm