It wouldn't happen, but theoretically if it did it could be hilarious.

The US doesn't look kindly on people who lied on official documents. Mostly this affects people who once came into the country illegally or overstayed their visas. That makes it nearly impossible for them to get citizenship later. So, if Musk had his citizenship stripped, he could be in a position where he could never get it back.

Additionally, the US has an exit tax for citizens who want to renounce their citizenship. That includes taxes on "Assets that haven’t been taxed yet but would be in the future, such as capital gains on stocks or funds in retirement accounts". So, if they hit him with that after stripping him of his citizenship, they could tax the hundreds of billions of unrealized gains in his various companies.

I agree that it's not going to happen unless something dramatically changes, but if it did it would be epic.