The interview in the story claims to be reported by the prisoner's lawyers. What prevents them from taking legal action now? What changes if their client is released?
Right now they still have "enemy combatant status" and are not in a position where they can push their defence any further or be helped by their own governments and/or legal systems (if said systems would in fact help: some would, some wouldn't). If they were freed without charge then they have a case for unfair detainment (where now any such claim will be replied to with "they haven't been charged yet, that might change") and if they were charged there would be something for them to try make a case against (where now it is someone's un-evidenced word against their's, neither side having much legal standing so the people holding the keys "win").