"height of the average white man"... So... height is white?
It will cost billions to redesign seats and their corresponding maintenance, since some airframes will require completely different seat and rail models for shorter individuals. That leads to all the ensuing logistics that entails. So much for hot-swapping pilots. "Sorry, we need another shortie to take that jet. It's got the baby seat in it. Putting in the big boy seat will take two hours with the inspections, including for the explosive actuators for the ejection seat."
Note that they said nothing about changing the seats (and deck beneath them) to accommodate taller pilots who have also always been disqualified from pilot positions. It's not just discriminating against male pilots anymore because now that 6'8" transvestite can claim to be one of the female pilots the Air Force is determined to put into a cockpit.
The sad truth of it all is that the Air Force has had trouble meeting their goals for years and they're trying to find anyone they can stick in a cockpit.
Bureaucrats just waive magic wands and fix everything. They assume an aircraft seat is just like the one in their Prius.