What would happen if Satoshi appeared out of nowhere after all these years and tried to sell some of his coins? Probably not much. First, Satoshi would have to move these coins to an exchange. That would instantly be detected because all of Satoshi's legacy addresses are watched. This would also mean giving up anonymity, since most reliable exchanges with any liquidity require KYC. Second, even if these coins could be sold, they would quickly be absorbed by buyers. If they were sold in large chunks, it could depress the exchange price temporarily, but it would soon recover. We'd all have a good laugh, a lot of memes would be generated, and we'd get lots of cheap coins to lock away for the future. Unlike premined proof-of-stake coins, no entity, not even Satoshi, has any more control over the state of or rules of the network. He would just be another participant.