What Fluff and Pete said.
My favourite series of novels, written by a male author about a male protagonist, has articles for every book including the one that never got published before the author died. The majority of them were never reviewed - they're pulp paperback novels - although there were some more in-depth reviews of the series, or occasional books that reflected the reviewer's opinion of the series generally. In fairness, there was a TV series based on the book series, as well as a bunch of Dean Martin movies that were (extremely loosely) based on the books too, so the series *does* have notability - but I'm not convinced every individual book does.
It's a classic example of "someone wrote it, there are no extraordinary claims, and it doesn't hurt to exist", I think.
I suspect what red-flagged the October (novel) article was the creation of a new category for it, because it drew the attention of a different group of people who might otherwise never have paid attention to this article. They're more wrapped up about categories, generally speaking.
Risker/Anne