This. I can see how getting blindsided over a DNW like that would make things difficult for some authors (which is also true for a number of other DNWs), but if you see a letter with that DNW and know it'll give you trouble, do the same as you would with any other DNW that interferes with your view of canon and what you can write: accept that you're a bad match and unoffer the fandom (or prepare to default if you get matched to it).