Feminism is not a monolith anymore than 'women' are. The outfits aren't a problem per se. The entire film is typical Snyder, i.e. lacking in substance no matter what it pretends to, hence my use of the term 'vacuous'. And if you can't land the message what are you left with? Action porn.
I'll even view the film again, now, years later ... to see if I change my mind.
And if Snyder's big feminist moment is martyrdom does that say something about the best women can expect? It's another case of failed communication.
I think the message is there, and the genre of the film fits to serve that message. I just think the message and story are both intertwined heavily and both are pretty simple. So it comes down whether you like it or not.
As he's already said, both genre in film/animation and comics use women in sexually aesthetisized manners. Many women and girls go dressed to cons as these very characters also. But what the film does I think rather clearly in costume and in autonomy is reconcile that it doesn't have to be at the behest and benefit for men solely to enjoy, as in to view women dressed in revealing outfits or for their entertainment.
The characters use their sexuality and embrace it for themselves, not for others, and they manipulate and form the agency of the story despite the men in the film trying to literally contain them/render them functionless ie the lobotomy.
So this goes quite hand in hand with women reclaiming what they choose to wear as something primarily or solely for them. Or taking action no matter the outcome and not being pliable only at the hands of men.
But to negatively view how they dress as titilation just for the male audience I think is missing the point in every regard. That is to say that women can only be dressed a certain way or viewed a certain way, yet male characters in films like Magic Mike, 300, any army film or action film are allowed to be as unclothed, clothed or provocative as they like. So again, to ridicule what they wear in film is itself an act of the audience actively saying how women can and can't be portrayed. And so his point of well this is allowed in comics and manga etc. but not in this is quite fitting. The fact it causes quite a debate actually works in favour of the films message for me personally.
Also I don't quite think the overall message was martydom, I think it was more along the lines of the true meaning of existentialism, as in its purest form, you are in control of yourself, regardless of the situation you find yourself in you have the choice and freedom to choose. No matter the outcome it's yourself who must take control of your situation - manifested in this film as to use their situation in an unexpected way to escape from the hospital. The end result is just an unfortunate byproduct of what happens to many women who try to do the same thing, abuse or murder, it isn't the film saying look if you try to do something this is what's going to happen to you, it's saying you've got the power to do something - which is pretty much the definition of empowerment.