If someone can sign a message with genesis？

[apogio]

Personal opinion:

If I saw a message saying "I am Satoshi Nakamoto, the inventor of bitcoin and I sign this message on 2023-12-19" and I was able to verify the signature, I would only believe it is the true Satoshi if they didn't show any real life identification. If they did, I would probably think they have gained access to the private key somehow, but they are not the real Satoshi. (cough, cough CSW potentially claiming being Satoshi)