Voted for I’m not sure.

It is depending on their future decisions.
If they sell all of it, and the price of Steem will go down, and they buy more Steem later with that money, then I am happy with their powering down.
If they sell all of it, and the price of Steem will go down, but they don't buy any Steem with that money, just keep the fiat money, then that is probably not good for Steemit, so I would not be happy with their powering down in that case.
But I would not be unhappy with it either. To be honest, I don't even care about it.
Steemit is becoming a ghost town anyway.
This would only be an additional push (or more likely a mercy killing) in that process.