Ah, but we're not talking about the Olympians, we're talking about the Truth. The lasso is not an Olympian power. The lasso works every bit as well against Olympians as it does against mortals. Their rise and fall is incidental and irrelevant to its effectiveness.
Further, Darkseid can't have re-written reality in the way you posit, for the simple reason that the ALE wasn't irresistible. You can paint shit on your face to stop it from affecting you. You can get kissed by Flash and that stops it from affecting you. You can cut off the transmission before you hear it and that stops it from affecting you. That's not a reality rewrite. If it were an immovable object-irresistible force thing, that would be one thing - it no one is exempt from the ALE, there's almost an argument there. But if the ALE's mind-control can be resisted, the lasso must be one of the things that breaks it, because the lasso is an irresistible force. And the ALE can be resisted, and is therefore not an immovable object. The lasso wins.