I haven't read it yet, but when I saw your post I glanced through it, and it looks a bit more ambitious than most fan fiction. No offense to fan fiction! Just that it seems -- on that quick skim, anyway -- to have more ambitious artistic goals. But now I'll have the fan fic fans and authors feeling insulted.
I'm trying to think of an analogy. I would say it's like calling GWTW a historical romance novel. But that's not really a good analogy, because basically that's what GWTW is.
Well, I'm being snarky in calling it "
Brady Bunch fan fiction," but if somebody else, an amateur writer, wrote a back story or prequel to the TV series, I think that's what it would be, fan fiction.
And they might even have the lawyers of the show's producers, or their heirs, after them for copyright infringement.
I assume this guy got any necessary permissions, or
The New Yorker wouldn't have published it.