I said what I did in the other thread because of a little word that no one has actually said.
Some genres are descriptive: Mystery, fantasy. And those plus others are treated as "genre fiction" (a term that means, "not a serious literary book," despite the fact that we can all come up with multiple examples saying otherwise). Romance is a genre that gets called "genre fiction." And often it is books that aren't meant to be literary and don't take as long to write. Westerns, some detective novels, etc.
What we're dealing with here is the label "women's fiction." Which, sure, is an actual industry term. But I can not hear it without also hearing the "just." It is just women's fiction. It will never be serious literary fiction. No matter how much work an author has put into it, it's just genre fiction. Romance that isn't romance.
And that's been the truth for forever. Female authors might write and sell books, but they weren't considered "universal" writing. In part because women gasp wrote about other women, or girls, or domestic situations, etc. I'm not making this up. I learned it in English class (and a million other places). I'm in my 50's and things were starting to change at that point. So my English teachers talked about how wrong these assumptions were, and how utterly entrenched. There were highbrow essays debating the question of if a female author could ever write something universal.
Even here in 2018, my daughter is in 8th grade and the entire reading list for the year* is white male authors writing about white male protagonists. Lest you think this was all a thing of the past. Despite a teacher who calls herself a feminist (she is constrained by the approved list of books to choose from). * There was one maybe book by a white woman writing about a white girl.
So is women's fiction a genre? Eh, probably. Because it meets the definition. But I refuse to treat it as one. The question you link to wasn't about sections of a bookstore or marketing, it was about the genre one is writing in. With my own work, I don't aspire to be a shunted-to-the-side marketing category. If I write within a genre (and I do, as my novel is middle-grade and fantasy), it's because I embrace it. Not because I think it is just all it can be.
If the novel in the question is published and then marketed a certain way, so be it. That's on the publishers (and distributors and bookstores...). But should that author aspire to and embrace her book as women's fiction? Yeah, no. I mean, she can do whatever she wants, but I'm not going to suggest it. Or let someone else suggest it without comment.