It seems that Satoshi Nakamoto vanished shortly after Gavin Andresen replied with an email to Satoshi that he (Gavin) was going to visit with the CIA.
He surely didn't appreciate the invitation to the NSA, but I doubt that was the reason of his departure. In case you didn't know, that was their last conversation:
http://gavinandresen.ninja/eleven-years-ago-today.
Only way to do that would be to rewrite the code and have a hard fork which no one would run since it would cause chaos pretty much.
Hardforking creates an altcoin. Even if the overwhelming majority of the Bitcoin userbase switched to that hypothetical hardfork, it wouldn't really be Bitcoin.