That’s a different scam that has been going on for years. They phish/crack random, usually inactive, verified accounts. And then they chance the display name / profile picture to Elon’s. Then they reply to his tweets with this message

Those have been happening for a long time before this, and consist of taking over some some little-known verified account (presumably through phishing, password reuse, and other such conventional means), changeing the (non-unique) display name and profile picture to Elon Musk and doing some bitcoin scammery. The actual well-known accounts are unaffected.

I believe that’s just a fake screenshot of an Elon Musk tweet.