:welcome: Nothing new with that, it has been happening for some time by now.
The Stihl models that I have seen unlicensed Chinese copies of, promoted trough E-bay, is the 070, 380, 038 and either 270 or 280. There are some Husky copies also, but I don't remember which models.
If the seller is in the Western world, and offering just one saw, that is something new, though.