The word is being used descriptively. Opposing the National Socialist German Worker's Party doesn't mean you oppose socialists, because those aren't socialists. You could have said that a/i isn't antifascist, but you didn't say that.

I didnt say they weren't antifacist because its both irrelevant to my point and i dont know nearly enough about them to claim so.

In the case of antifa, the content and the label are congruent. They are, literally and practically, anti fascist. That's not the case for the NSDAP.