Unless they transition before they’re 12? What kinda [bleep] up [bleep] is that?
I'd assume it has to do with hormones, especially the changes in the male body. Stop the hormones with hormone blockers at a young enough age and those physical changes and differences are lessened or don't exist.
Ymmv
Yep, their job is to ensure fair competition, and it stops there. If they cross the line and get into morals, they'll lose.
So I say, good idea to stick to the fairness of competition. No one can argue that.