Trump's no dummy. That he turned his back on his (former?) alt-right supporters was a point of consensus among he and his advisers. They weighed the pluses and minuses and decided it was best to "publicly" cut his ties with them. Like so many other of his edicts, promises and other sundry alarming rhetoric, Trump will say things "he doesn't really mean" or says things for advantage over his rivals......IOW, for many reasons other than the stated or apparent one.
He may still support them and their wishes, just not publicly. Let's see if he really doesn't care to be associated with them from observing his future actions in this regard.
It may be that Trump feels it would be quite easy to regain their confidence (if they did) when he will need their support in future elections by simply firing up the 'ol rhetoric machine once again. If it was easy then, why not again....and again...and again?
I mean, the alt-right folks aren't any different than all those other folks he wooed into supporting him in the sense that they believed in his words no matter how horribly he behaved or spoke of others. So if that's the case, I would think he considers all of those who voted for him as being unshakably loyal to him because as he said, "he could shoot somebody and they'd still vote for him."