It is harmful, not just for women but for them too, I wish people wouldn't dismiss autogynophilia all together. A lot of transwomen have said their partners end up transitioning themselves, which isn't that much different from cross dressing men who seek out cross dressers because they're cross dressers themselves, what researchers know is men who view transgender porn (and I'm guessing seek out trans partners and end up transitioning based on what I've heard) were studied they are autogynophiles?(-philiacs?). It's not really all people with gender dysphoria I worry about (though I still strongly disagree with the idea that we should get rid of female centric spaces which they're considered "cis" therefore "privileged female bodied" spaces), it's the "you don't need gender dysphoria to transition" people who are most likely fetishizers and they're doing themselves a disservice by not acknowledging that and exploring that part of themselves privately.