I don't know if the alt-right people will brush this off as a misunderstanding, but from what I've read concerning the A-R universe, Spencer is a huge deal. He is supposedly one of their leading lights although I will confess to never having read much of what he's written or listened to him speak on video.
I don't know if Trump even knows who he is.
He, Trump, is the hero of the A-R, but I doubt he pays much attention to anything they espouse. I don't like Trump, but I'm not going to ascribe nasty things to him if I don't know they're true. And I've never read anything from him where he welcomed A-Rers.
They say that Steve Bannon has connections to the A-R, but I don't know if he's told Trump much about that. We shall see.