The sort of Doctor I would want my child seeing would be aghast at this type of unnecessary procedure.
Plus isn't there the matter of privileged medical information?
So a young girl who goes to a Doctor and is told that there is something that would make her run afoul of these ballot measures won't be outed, they will just not progress with joining sports. The external difference between a "trans" individual and a girl that won't or can't comply will be nil. They aren't going to get a gotcha, they are just going to get reduced participation.
Does this mean when the fascist pricks that have pushed this shit don't have hard figures on how many trans kids they have barred from sport they will just take that whole number and claim they have kept that many "trans kids" from sneaking into women's sports?
Fuck this whole steaming pile of shit gets worse the more I think about how a maximally evil person could manipulate this to push a fictional world view.