any acquirer of gox would be legally bound to take on ALL the debt. not just a portion of it. If the company is so much in the quagmire that those debts are unsaleable, either current gox, or future gox would be forced into administration, and could write-off/CVA a lot of the debt. this would be the worst case scenario.
That would be true of a purchaser acquiring the company as a whole, outright... but if Gox was selling off assets in pieces, the debt would remain with Gox.
This is why it's important to put Gox into involuntary bankruptcy - to prevent "dissipation of assets" and take control away from Mt. Gox management.