I'm a big fan of Nier and Nier Automata and I had to work around a few things to enjoy the raid actually!
I don't like the concept of shoving a whole game world / setting into another. It gets so much Automata-y that I kind of forgot I was actually playing FFXIV, or at least I felt a bit confused about it. And if you want to be really the annoying lore person, there's quite a lot of Automata base concepts that make no sense in FFXIV's setting, or have an awkward justification.
Now it is quite well designed, self contained, does what Nier does rather well, and from an FFXIV gameplay perspective it's good. I find it a bit too easy but maybe it's my taste.
So my concerns would be to get a "y tho?" feeling by the end of the raid quests (so we have quite some time). If I wanted to play something with a Nier Automata flavour, well I'd play Nier Automata, it has a great replayability value. The introduction is not that interesting in my opinion, so let's wait and see.