President Trump's attitude, which tends to be anti-Bitcoin, has raised the discourse that he could forbid the ownership of Bitcoin for citizens of the United States (US) in the future.
This discourse is based on two possibilities, namely Trump's tweet in 2019, that Trump is not a Bitcoin lover and second is a recognition of Trump's similar attitude, as stated in the book by John Bolton, a former White House security adviser.
If he is anti-Bitcoin, then Trump have already issue the hammer ban already. But he didn't and just completely trolling everyone with his tweet, I would say just ignore it.
Responding to the discourse of a possible ban on Bitcoin ownership, many people say the most likely action is an aggressive step by the government in dealing with laundering crimes related to Bitcoin and other crypto assets. Direct banning seems impossible, because Bitcoin is practically outside the structure of the country.
Again, Bitcoin ownership doesn't pose a threat, they should look and trace fiat money because that's the majority of money laundering, terrorism fund are coming from. And going by your argument, if they ban Bitcoin will mean less money laundering? No, so I don't think that it is Trump's priority right now. He should be looking at the current unemployment rate and how US economy will recover because of the pandemic effect.