Do we know if there was indeed an "if/when" clause to "fix" The Augments? If their intention is to leave them frozen forever, that really is no different to execution.
But, yea, if there is no agreed Sentence Period and it's completely arbitrarily forever, then you can be sure, one day they'll escape (Even if it's not for thousands of years), and they'll be pissed with good reason. If there's an agreed sentence period or ability to deal with them, then there's hope for a rehabilitation (Though are they proud of who they are, and don't want to be neutered? We don't even neuter Pedophiles)