Quote Originally Posted by Erendis View Post
In what way are they canon? They are about as canon as FFXV and FFXIII events if not less...
The NieR raids are permanent, alter the landscape, and even now have a weekly questline. After the very end of the raid, it's finally explained why everything is there and is out of place (though I have no idea why the First and not on the Source?). The FFXI, FFXIII, and FFXV events were all temporary and have no mark at all in the game.

It would take some mental gymnastics to explain that the trashed dwarf town and giant space station that you can see from Kholusia don't exist. Judging by the weekly quests, we're going to see more NieR stuff out in the open world soon as well.