We need all the solutions
We think of the “homeless person” and the “moved to North Carolina to be closer to family and also to afford more space for the kids” as two entirely different types of people. But it’s a single underlying phenomenon. And who ends up in which category will come down to a mix of luck, whether or not you do in fact have family in North Carolina, and whether or not the forces pushing you out of the high-cost area come up on you slowly so you have time to plan.
The fact that the new buildings are not “affordable housing” in the regulatory sense doesn’t mean that they have no impact on affordability. Nor does the fact that a person existing on the margins of homelessness would be unable to live in such a building change the fact that allowing their construction reduces homelessness by increasing the affordability of other units.