I don’t assume anything about what comes out of his mouth, but it’s serious enough that I’ll take it at partial face value.Assuming what he said is 'gospel", the US Military could come in and build a couple of camps in Gaza, place refugees in there, while they clear the roads of rubble and debris and set up aid stations. Then hire Gazans to construct new buildings to the specs supplied by Americans with them overseeing it. Those that work can earn money and perhaps even title to some of the places they build.
It's full of risks and things to go wrong. Done right you could undermine Hamas in the process, a bit like a Briggs Plan tailored for the region.
Indulging your hypothetical, the U.S. military has no legal right to invade Gaza nor to force its occupants into camps. Were they to do so anyway, they would be right back into the sort of long term occupation of foreign places that a Trump has made noise about getting end of.
How many dead American soldiers and how much spent U.S. treasure do you think the U.S. population would tolerate for the sake of building apartments and schools and clinics in Gaza? Because it would cost a lot of both.
In any case, at this point it’s merely mouth noises from one of the world’s most accomplished bloviators. Hopefully adults in the room simmer this idea down.