Mt. Gox answered the curiosity about BTC sales in the last statement.
As known, in the course of the bankruptcy case, the pensioner made the payment of non-monetary assets (btc) in the form of fiat money. It says that it is now undergoing the Civil Rehabilitation phase and at this stage it has stopped making monetary payments for non-monetary assets.
In other words, Mt. Gox will no longer sell BTC, but will pay the victims in the form of BTC.
Another interesting explanation is that Mt. Gox claims that they have sold the bitcoin when their selling had no effect market price.
Click here to see full document.