It's the equivalent of years of unrestricted doping. Yes, their testosterone levels might be low now, but they've had the benefit of much higher levels than is legal for a woman for a long time.
Maybe it should be like disability sports, various categories for various levels of transition.
Sooner or later a trans woman (or is it man, not sure on the terminology) will kill or seriously injure a woman in a contact sport and then it will all kick off.
Better still, their own sport with their own funding ...
.... lets see how far that gets them.