pg insomuch as he's said anything about Trump has been anti-Trump as a person and political leader.
MAGA itself has grown into two wings at this point, though, the classic Christo-fascist wing and then the techno-feudalist "butterfly cities" section, with some people like noted couch-fucker JD Vance bridging the gap between them.
Garry Tan, whether he has officially endorsed Trump or not, has deep ties to the latter half of the nu-MAGA coalition and the majority of his public speaking post-COVID has been aligned with that political ideology, the main adherents of which seem perfectly willing to use Trump as a vessel to achieve their goals.
I suspect at some level these people are kind of annoyed by Musk despite their goal-alignment because one of the main things he is doing is moving too fast to the point where he is drawing a lot of attention to their movement, which would be better off (in terms of survivability) if it were a bit more shadowy at this stage. But Elon is ultimately a 4-chan child that can't help himself and will bring everything crashing down on their movement.
This trying to make up the bad guys said stuff they didn't say schtik is kind of pathetic. Musk is doing so much real bad stuff and this just justifies the whole 'fake news' narrative by being fake and so detracts from the real horrors.