If he and others that are powering down decide to sell all of it. What will happen to the price?
I think it doesn't matter much if some whale sells a lot now. Steem already did amazing curve. People will be looking on charts and think: "Wow! If Steem was rising in the past - good chances that it will rise in future. "
We will end up with better market cap and more users anyway...
We will know more in a week after the new round of power downs what the market thinks.