Unfortunately, because we're not at war with Russia it can't count as treason, but there's a whole host of other laws he violated so they could definitely get him on something.
Actually, subverting the foreign policy of the United States is actually a form of treason.
Like, you can say "I think we should trade with Cuba"
You cannot provide funding to a company that ships aid to Cuba. That is illegal, and actually a form of treason.
What Musk did is the latter. He saw a geopolitical situation the state department was handling, and inserted himself and his company into it. Up to thst point is fine. But then he inserted himself into the decision-making process of US strategic command because we was a vendor to the government.
If you supply rockets to send up satellites, the time to object is before you agree and load payloads to send up satellites. Not during or after.