As far as I know it is not considered core by WW. I think it's because the quality of meat is unknown. That being said, I eat it as core when I want/need it.
We have a Wendy's very close to where I work; and we end up there on Friday's quite a bit. I have ended up going with the chili on a few occasions, and I consider it "core" when I have it. It seems like one of the better options on the menu.