Women (and trans women) naturally carry a higher body fat percentage than men (Incl trans men) a “male” athlete can more safely and more easily carry a lower body fat % and therefore more muscle per kilo. So the weight classes wouldnt be able to be 1:1 if you wanted a level playing field.
There is still the inherent biological advantage in being born male and going through male puberty and developing a male muscular/skeletal system before transitioning. Very difficult to rule around every nuance of this though.