Under the federal constitution, the power to manage the monetary system rests with Congress, the Treasury Department, and is supervised by the Federal Reserve. The only thing the president can do is make a proposal, he does not have the unilateral power to do that.
Yes, all decisions are on multiple sides so whatever the deal is, Musk can't go it alone. It seems like Elon Musk's response to making the party was because he was disappointed in Trump. Trump's decision to make tax cuts made Elon choose to leave Trump's supporters.
In general, it seems that Elon will be more into technology development. I think this party will bring the issue of crypto being used as a tool, like Trump. We already understand how politics works, so don't trust 100% when it comes to politics.
But on the other hand, I'm quite happy that more and more influential people will pay attention to crypto. It means the future of crypto will be better. But another condition is the policies that we sometimes don't like, because sometimes economic policies conflict with crypto. We have felt this in the Trump administration.