Realistically, nobody has the willpower to not dump their 1 million bitcoins when BTC reaches $20,000 each.
He would have had a net worth of $20 billion.
I don't care if you want to reshape the world or whatnot, $20 billion buys out the morals of almost anybody. He must be dead.
He wouldn't be able to cash out more than a fraction of his purported stash without crashing the markets, and I can't imagine the markets reacting positively if it was clear the creator of Bitcoin himself wants to sell as much as possible at ATH. If he's alive and still has the private keys he's probably financially comfortable enough not to care about having more money.