I could see it potentially making less money if the whole cold war spy thing doesn't spark as much as typical Marvel superheroics beyond just sexism. As for Charlie's Angels, I think it might have done better without tying it to the franchise. I thought it looked awkward as a take on Charlie's Angels and in interviews the girls seemed clueless about that but would've bought it as a millennial take on an action spy thing. Hell, it probably would've killed as a Disney+ deal actually, no insult meant, just seems like a good match.
I think what you're saying is, and correct me if I'm wrong, that if the movie isn't a good enough story, it won't do as well. I think that's far more likely a cause than sexism, as other women led movies have shown. Wonder Woman was a good movie. It did well.
I think they should market it as any movie that starred a man--and not play up the gender thing. In Natasha's case, it never was a thing at all. She's a hero that happens to be female. Her gender should have nothing to do with anything.