If the Empire was trying to trick a group of people into being prisoners for life, I imagine that pretending to release them only to give them a new sentence would only work once. Maybe the prisoners are ‘released’ only to be transported to the neighboring prison building for the remainder of their life sentences, and one prisoner was accidentally placed back in the same building in a different level, at which point the game was up.
But wouldn’t they just be like “…hey I was supposed to be released!” to their new team, and then we end up with the same problem?