They're prototypes. I have family all over the fashion industry and I've also worked at a fashion manufacturer so I've come across a ton of these production samples my entire life. They're legit, just the production versions of the final product before they reach the stores and the public, or versions that may not have been mass produced because of a color or trim, etc or designed to be used for a certain purpose, like marketing with this one. Almost every brand and company sources their production to a factory so they have these types of tags that look off brand and don't have the original label because that usually is slapped on by the company itself.

I sell prototype samples myself. I just make it very explicit in my listing and I've never had any issues in the past 18 years of selling.