For all we know, he has. We don't know what sort of pressure he has applied out of the public eye. His remarks this morning were in response to a question.
And even if he hasn't, the dishonorable candidates have free will, and there is plenty of value in letting them show their asses. Trump's success doesn;t depend on them, thank goodness, and the party does need a good, thorough house cleaning.
House and more importantly, Senate cleaning.
Most of the GOP Senators are Cheap Labor Express stooges and Nevada is going to elect another one, Joe Heck.