I think i guesstimated that GOP will axe the Trump brand around summer. Establishment politicians aren't known for doing anything remotely spontaneous. They avoid burning bridges that cost them votes more than anything. I'd be surprised if there weren't some assurances to select individuals that they could openly go against Trump.

Their bet is that they will get back the votes and financial contributions by 2022.

I wouldn't exactly say Trump went after the swamp, but he did burn bridges he didn't need to burn and he didn't play ball. He mostly did that to enrich himself and being a retard, but the end result was that he fucked with GOP's money. They will never let that slide.