Most likely Trump proposed the idea and it fit with Bibi's plans to get rid of the Palestinians, he just doesn't have to kill them. I'm sure some combination of Trump, Kushner and/or other developers made plans for this "Riviera of the Middle East". Probably building models right now if they weren't already.

To Trump there are no negatives to this plan since the plan is to make money. All he has to do is strongarm another Middle Eastern country, or two or three, to take the Palestinians. He can't conceive how this will affect the Middle East in general because he doesn't understand or care.