I think that is only part of it. Musk gave an interview where he talked about how the woke medical establishment trans'd one of his kids. They falsely told him to do the transition or his child's death was a near certainty. European countries are now restricting this "treatment" for children. The US has been slow to follow. There is a lot of money and political pressure from the left to keep the medical intervention industry alive.

You don’t spend that kind of money and risk alienating your entire customer base (and future workforce!) just because of a slight.

Musk is getting something from Trump: most likely protection from some legal issue.

Musk has never, no matter what he claims, ever a progressive democrat. He would be at best, someone who believed in the liberalization of certain drug policies. His economic beliefs have always been max pro business (aka, hands off, anti labor). He solidly fits under libertarian like the rest of the tech billionaires. Republicans, if it weren't partly driven by Christian fundamentalists, would be libertarian. The conservative GOP party of the 70's hasn't existed in decades.