From a financial standpoint, this makes no sense.

First, they could just liquidate all their other BTC before moving the Satoshi coins.

Second, even with a significant price impact, the net worth of an additional 1M BTC would surely outweigh any realistic price slippage.

Third, the price probably wouldn't even crash that much. We're talking about a 5% increase in supply... which rationally, should result in a ~5% dip in price. I know the market would overreact, but I doubt it would be by much more than say 20%.