Transferring crypto to an exchange is not the same thing as selling. I myself have quite a bit of Steem on an echange that I use for regular trading. It might not be the most secure thing, since the exchange could be hacked, but it allows me to profit quite a bit from trading.

He could have done quite a number of things, including diversifying his crypto holdings to weather to bear market. The question is, if he has sold Steem, will he buy back any? Will he possibly increase his holdings?

In any case, it's not really our business what someone does with their personal holdings of Steem. Despite people's grumblings about people powering down, it is fully their own business what they do with their own finances.