No. This wouldn't be a problem, as the market would quickly grab them. Besides if Satoshi wants to change it for fiat, i'd say let him/her.

If you think this would harm Bitcoin, you are very wrong. Cheap bitcoins? Others would grab them. It doesn't matter who sells them, don't fear the whales, if you have fiat lying around a lower bitcoin price would be your chance.

But its all wishful thinking, you never know when this will (if ever) happen, Satoshi or any other whale, can sell at anytime; don't fear the inevitable, embrace it, understand it, then profit!.