Uldren's already been punished via execution then being reborn as the one thing he hated most (a Guardian). Now that he no longer remembers what he did (and if he did learn of it I doubt he'd just go back to his old ways), I'd say it's time to forgive. We don't need him becoming an enemy yet again, and his presence may prove key in finally getting rid of the Scorn permanently. Variks is more questionable since he was completely aware of the consequences of leaving the prison in disarray, though Cayde's death was ultimately collateral rather than deliberate. I won't hold Cayde's death against him as a result, but I think he should be held accountable for the prison break after Eramis is dealt with (whether that be being locked up there himself, returning to his original duty, etc).