Priebus played a major role in the Donald’s victory - he earned the job and Trump recognized it.
That may be true, but Priebus is a very close friend to Paul Ryan. They grew up and went to high school together. This could bode poorly for serving Trump, and molding Trump to the will of the feckless House. Or, it is possible that Priebus could put the squeeze on Ryan’s onions.
I’m not about to second guess Trump. The man knows what he is doing. In Trump I trust.