Once the judge allows MtGox to enter Civil Rehabilitation then the remaining 160K btc are not governed by bankruptcy law which required cash payouts to claimants. The remaining bitcoins are merely corporate assets that must be returned to stockholders. And the stakeholders Karpeles, and some would argue, all his customers overwhelmingly prefer bitcoin to cash.
Since there will be no legal reason to sell the bitcoins they will not appear on the market.