But his account has blue verified check mark at least.
Blue checkmark is not a sign of authenticity since Elon Musk bought twitter, now it means that the account owner bought twitter subscription. But even if the checkmark still was about authenticity, it would change nothing - no one knows Satoshi's identity, so no one can verify it.
Exactly, I'm surprised that it took several posts before finding yours that explain how Twitter, pardon, X verification process works since Musk's buy out. Anyway for me the account is definitely fake, I mean, Satoshi disappeared from this very same forum which is full of very useful information, why should he join Twitter in 2018 instead of being active again here?