Priebus won't care about carrying water for Trump anymore on November 9th. And if he did, there's nothing much he can do to "retaliate" against these guys. Party chairs aren't that powerful.
He can probably strong-arm the rules committee into just about anything. They wouldn't dare go against the party chair, probably.
I mean that he's not that powerful in the sense that he won't try to exercise his hypothetical power if he's not getting support from the rest of the RNC, and the rest of the RNC isn't going to be interested in pushing this too hard. Neither will Priebus himself. None of them will care about punishing these folks after November. And what would the punishment even look like? Rigging the next primary season to disadvantage folks like Cruz, Kasich, and Sasse? What kind of rule change would even do that?
Not sure about Sasse, but Cruz, Kasich, Jebra, and I believe Graham all signed pledges to endorse the eventual nominee, unconditionally, to get on the ballot in several states, including the key early state of South Carolina. Priebus could try to strongarm the state party into prohibiting them from being on the ballot in those states in 2020/24 (depending on whether Trump wins this year), or strongarm the rules committee into not seating any delegates awarded to said candidates from those states, or only seating half of such delegates - on the basis that such candidates gave a willful oath to the party that should have consequences if it is ever broken.
But Trump himself said that pledge didn't matter any more.
