The timeline went something like this:

Generic Male Marvel Fans: Trailer looks kind of generic, maybe I'll see it, maybe I won't. Marvel usually delivers, though.

Brie: (Insert slightly prejudiced virtue signaling)

GMMF: Oh God, don't start this shit, please? Come on Marvel, you know better-

Media: MISOGYNISTS EVERYWHERE HATE CAPTAIN MARVEL BECAUSE THEY CAN'T STAND A FEMALE SUPER HERO!

GMMF: Wait, we never said that, and there's a whole slew of movies with female protagonists we enjoy. But why deliberately -

Media: WHY IS FRAGILE MASCULINITY SO AFRAID OF THIS MOVIE???

GMMF: You know what? Go fuck yourselves. I really didn't care before, but if all you're going to do is insult me, why should I give you money?

Media: NECK BEARD INCELLS ARE BOYCOTTING THIS FILM! MISOGYNISTS EVERYWHERE!

tl:dr - The film was a victim of manufactured and deliberately farmed outrage, possibly to try and bolster feminist support.