I think it's less of an onus of "she will fix everything because she's a women" and more "a woman made it this far and thus things may change for the better". But the problem is, when such misogynist (or racist, or whatever other -ist you want to think of) system exists, people who are mistreated by that system often have to accept and often promote that kind of system just to get to a position of power.
It would definitely be nice if things changed for the better, but it's going to take a hell of a lot more than one person at the top to make that change. And, for all I know that change is already happening, and is part of why Admiral Franchetti has gotten to the place she has.