Is this a serious question? I don't think satoshi gonna create an altcoin when bitcoin is already established and going strong, I mean, what's the benefit for satoshi to create another altcoin?
Imagine if he really did, I'm pretty sure bitcoin's market cap gonna be torn apart and there'll be fraction of people believing the new coin is the real bitcoin just because it comes from satoshi himself, and the rest will keep on holding the bitcoin. It brings no real benefit at all and i think he prefers the community to grow the blockchain.