More time travel nonsense (assume full MSQ spoilers):
They should have left it at alternate timelines. Closed time loops require too much in the way of mental gymnastics and suspension of disbelief. If there's a timeline in which the WoL dies then there's a timeline in which the Ancients survive.
I'm well aware the game's narrative undermines criticism. The push to make Venat/Hydaelyn some sort of tragic figure of good intentions couldn't have been more heavy handed from Thancred immediately throwing his support behind her because of Minfilia to Y'shtola repeatedly giving exposition speeches excusing everything she did. However, fact of the matter remains that the omniscience we gifted Venat only extended to the point at which we journeyed to Elpis. The potential of failing the trial against Hydaelyn to never defeating Meteion (the more likely scenario due to a variety of factors needed to even reach her) meant Venat's gamble easily could have not paid off in the end, so I reject this notion that her method 'worked' and if she was so confident in it she wouldn't have made contingency plans.
As far as I'm concerned, the end of the game still could've played out exactly as it did while also giving us the opportunity to save the Ancients in an alternate timeline. The fact that our life as Azem and their best friends keep ending up on the chopping block for the emotional gut punches while the Scions remain indefinitely unscathed is simply not compelling to me. Like I said, I think the Ancients have the better story and characters of the two because of it so it's frustrating that they can't even be given one off-screen win.