Before I answer that, I should highlight a related issue from my old post on multiplicity:
Some of my fellow lefties are fond of diversity, but they only see it at the macro level - they espouse "cultural diversity", yet ignore the diversity within cultures.
But let us suppose that the women are so well indoctrinated that they do not object to the patriarchal cultural practices. Even then, I think, we have the basis for saying that they are worse-off than they could have been. How? Well, it's a question of well-being, so perhaps one of my recent posts on the topic can be put to use here. I think that counterfactual considerations in particular (with a dash of global preferences) ought to do the trick.
That is, we compare Oppressed Mary with her counterpart in that possible world where she was raised in a more liberal society, and had the educational opportunities which allowed her to become a philosopher, or doctor, or whatever. We then compare the strength of their global preferences. If Mary's counterpart would be more strongly satisfied that she had lived a liberated rather than oppressed life (compared to the strength of Oppressed Mary's submissive preferences), then that gives us objective grounds for saying that Mary would have been better-off with that life. By raising her in an oppressive environment and stunting her individual growth, her backward culture has harmed Mary. That's not the judgment of some uppity white male - it's the judgment of Mary herself, across the possible worlds.
(I should note that this might just as well end up criticizing Western culture instead. Perhaps, for at least some of us, if we were raised in less materialistic cultures, we would have more strongly prefered that life to our actual one. Who knows?)