Earlier quoted context omitted.
Lots of fiction writers use real people as the bases for characters; that doesn't make them "creepy internet stalkers". Cat Person was a work of fiction. There wasn't much ambiguity about that.
The presentation of the story is actually pretty subtle about it's fictional nature. Nowhere in body of the story does it say it's a work of fiction. Readers the miss the small "fiction" label in the header [1] could easily make the mistake of thinking it's a real story. And as per OP many did make this mistake. 1. https://www.newyorker.com/magazine/2017/12/11/cat-person
This is a bizarre demand to make of a work of fiction. How many fictional stories mention they are fiction in the body of the work?