I think it's more accurate to say that Nier in FFXIV is inconsequential. Yeah the events are canon, but they're so disconnected from everything else that it doesn't really matter.

I'd say the same is true in reverse too. No main story beats change as a result of this, it just adds some neat extra fluff around events we already know about, cool stuff for those invested in the lore but of no real consequence to most people.