surely there will be a very large shock in the public market. maybe I think it could cause a global panic for biitcoin owners. But Satoshi Nakamoto wouldn't do something stupid like that, there must be a bigger plan than worrying a lot of people just looking for a profit.
Nothing. He will be either to dumb (which he is not) to sell all his coins at once since price will dump maybe under 10.000 coins so by the time he would get to 100.000 coins price will cripple since there will be no enough liquidity on the exchange. No one sells bunch of coins at once. So We assume he is smart guy (which he is) and if he wants to sell he will go in waves of small quantities in longer period of time on different exchanges. Which will not be felt by the market at all since market is liquid on this level.