The simple fact that you're passing it off as 'trolling' says it all, really. I don't think you're coming here in good faith...but that aside, we've presented our case and compiled ample sources to back up our talking points and so the onus is now on you to provide textual or developer commentary evidence of your stance, since simply referring to a scene by name won't cut it as you do not seem able to accurately represent what is actually being depicted. Even the cutscene that you are alluding to does not refer to tempering, so much as the attitude of the strawman ancients to despair, and that is also discussed as part of her motives in the Q&A, whereas tempering is not brought up at all.
The developers have confirmed - per the story clarification Q&A that took place shortly after Endwalker's launch - that Venat can be read as trying to maintain the timeline for the Sundered's future, so plus the AU split for the 8UC timeline based on G'raha's actions, that also shows there was the potential to affect meaningful change, and so in addition to what Absimiliard has already said, Elidibus's words don't matter as we are already aware that it is possible.
Q: I don’t really understand why the Warrior of Light messing around in Elpis didn’t create any alternate timelines. What happened?This is consistent with:A: Well, I think the most important thing is that you can come up with your own theories for this one. In my personal interpretation however is that the timelines were always the same. Another interpretation you can have is that maybe Venat worked really hard behind the scenes to ensure the timeline didn’t go awry. Therefore the Warrior of Light was always acting in accordance with this plan of Venat so the timeline that we are aware of didn’t change when we went back to the affected. I personally think that when we went to Mare Lamentorum and we first met Argos and Argos really took to us when we were able to ride it, that's basically the proof that at that point, the timeline is going accordingly. We are adding all these stuff to New Game+ in 6.1 so if you’re interested in this I suggest you replay it and think about these questions when you’re playing it.
Q: I am interested to know how unsundered Ascians such as Lahabrea, Elidibus and Emet-Selch avoided being kicked into 14 pieces by Hydaelyn.An unfortunate consequence of what happens when a setting ties so much of its story to a handful of characters and lacks much in the way of content with staying power along the lines of Eureka, Bozja and Ishgard reconstruction.A: As you think back to the text towards the end Emet-Selch did imply that Venat let him live unsundered. In fact Venat did intentionally leave a tiny floor in her Sundering attack - a crack that Emet-Selch can wiggle through. Sort of like…yes it was a powerful attack but intentionally chose to do it in this fashion. So we said this in the actual game as well which is when Hydaelyn did the attack, it was a really strong one. It was delivered at the limit of her power so she couldn’t really fine tune it. So as intentional as this was when she did that big massive light attack that sundered the world, she couldn’t guarantee that Emet-Selch would live and she was kind of making a gamble. In fact what happened was, at the time that Hydaelyn performed the sundering, Emet-Selch was with Lahabrea and Elidibus (the time he was already out of being Zodiark core so he’s a little bit different than his original but nevertheless he was there) so they ended up joining forces, and escaped to the rift without being Sundered. You may recall if you read Tales of the Shadows that Elidibus, when he came out of Zodiark he ended up losing some of his memories as well as some parts of himself and that’s sort of the point in Patch 5.3 and when he “dies” you sort of know that he lost a lot in the process as well just like Emet-Selch. So yeah, basically they worked together at that time and escaped being Sundered.