Much ado about nothing.
If any part of the female genitalia were to be exposed it would be the vulva, not the vagina.
However and more importantly, if female athletes don't wish to wear this then should not be compelled to do so.
In my view, there is no significant reason why all should be required to wear a 'uniform' attire, in any case.
Male and female ought to be able to wear what, for each, is comfortable and conforms with their own idea of personal dignity.
If some uniformity is required, then it could be provided by requiring a simple colour code or similar.
If some athletes are more concerned about modesty than others then give them another option, such as shorts or optional tops and bottoms or one piece outfits.
What this all boils down to is the negative effects of money on sport. There is no justification for Nike being able to decide what athletes should wear other than that they have, perhaps but probably, offered the highest return to get the contract.
Commercialisation is ruining sport, if it hasn't done so already. Income is not shared with any sense of equity and the major benefactors are not sports clubs or athletes, (perhaps with the exception of those few at the peak of their sport). The major beneficiaries are media outlets, advertising companies and sport associated suppliers.
That ought to be the main concern here, though those athletes who feel discomforted or demeaned by any of these uniforms ought to have their concerns heard, not dismissed.