Bitcoin should be forked and Satoshi's 1 million Bitcoin destroyed completely, if he really owns that much.
A sudden withdrawal of of 1 million (or large gradual withdrawals) should be regarded as an attack on Bitcoin.
Or it should be frozen for now until developers are sure no one is going to withdraw the whole thing and crash the market.
That will not happen, because if he moves those bitcoins his anonymity will instant disappear... So he could become instant rich but not for much time because police would take him to jail before he could even touch that money.
But maybe frozen those btcs is a smart move.