[6.0 - 6.4 Spoilers] An interesting video detailing Venat's polarizing reception

[Absimiliard]

Yeah, none of that reads to me as a reliable piece of intel, because it's being told through the lenses of two different characters who are, to be brief, massive drama queens. Not only that, but both Nier and FFXIV are happy to twist and accentuate representation even to the point of hiding factual truths for the sake of underlining emotional truths; my favorite example there is the Tsukuyomi fight, but it's also been used in the Ancients' story through way of Venat's post-Elpis scene.

Once again, Mama's drama queen tendencies only show through when she is actively taking part in the story. Instances of her acting solely as a narrator, of which there are several, see those elements completely removed. Additionally, the FFXIV crossover is, and I stress this, not part of NieR Re[in]carnation's storyline. It's simply a thing that is there in some form, and while presumably also canon to that world (as the NieR raids were on FFXIV's end, per the terms both teams agreed to), it's not something relevant to game's overarching plot at all. It's also not really being told from Emet-Selch's point of view. He is the character upon which the story focuses, but he plays no part in its actual telling outside of being one of several "actors" involved. That was kinda their intention with the crossover - it was to be his story, not necessarily that of the ancients. Not a story he participates in telling, but the story of his part in things. The crossover announcement and promotional materials corroborate.

Now, the interesting thing that one could bring up here was the Twelve. We get their story several degrees removed from that origin point as well, but there are new factual pieces to that 'immediate post-sundering' time, if that's what you care about: namely, the Twelve's yokes. These were things that needed overseeing in the immediate wake of the sundering; therefore, not only can we take as a given that concepts like glaciers, the tides, and time existed, but that they were at that point shaky enough to need some guiding hands to make sure things didn't fall apart.

It stands to reason those things, which were part of the world prior to its division, would remain in some form afterward. I'd have been more surprised to learn they were for some odd reason absent. I do find it logical they were unstable enough to require supervision immediately following the Sundering. Perhaps less so time since it's something of a universal constant (gravitational influences notwithstanding, of course), but I suppose that comes with the territory when you divide something into fourteen separate yet connected dimensions. It tracks that a blatantly unnatural event would have equally unnatural consequences.

but most interesting to me is Byregot: construction and 'fortifying the works of man' only make sense if people are actually building things, which suggests to me an element of stability and advancement that isn't there in Emet's retelling. (And of course, that element's not there in Emet's retelling because he doesn't really care; both his and Mama's retellings of it focus on his emotional pain, and his feelings don't care if they're building things.)

I'm not seeing the conflict here. We've ample reason to believe the sundered were in extremely poor condition immediately post-sundering, but that doesn't mean they would remain as such forever.

So if you consider the crossover event of no count, what do you consider acceptable sources other than FFXIV itself?

[Cleretic]

So if you consider the crossover event of no count, what do you consider acceptable sources other than FFXIV itself?

They all 'count'; they're just not providing new information. That's actually pretty much universally true across the games FFXIV's had 'actual story' crossovers into: FFXV, Monster Hunter, Nier Reincarnation, Dissidia (both NT and Opera Omnia), none of them have information about XIV that isn't in XIV unless you count unusual character interactions like Dissidia NT showing what Y'shtola does when she doesn't have anything better to do, or the timeline weirdness of Opera Omnia having expansions-era Alisaie and Lyse interacting with ARR-era Scions. There's also someone summoning a primal in another world in FFXV, but I don't think anyone considered that too surprising or impossible.

The way XIV's writers write/authorize external content isn't in a way that makes otherwise unrelated media essential reading. Some franchises do that: some RPGs make their Japanese-only audio dramas canon, some MMOs shunt important scenes into tie-in novels, some movie franchises disclose important lore through Fortnite. But XIV doesn't do any of those; when there's a XIV event in another game, it provides interesting hooks for that game's crowd, and a fanservice nod for the FFXIV fans; it doesn't provide new information.

So to answer your question: it's not that you picked a collab event I arbitrarily don't think is an acceptable source, they're all acceptable sources... that never tell us something we don't already know. (EDIT: Which personally, I consider a good thing: I don't want to have to play a limited-time collab event in a gacha game for another franchise to learn something important about the game I actually want to play.)