This already exists in Samoan culture outside the kind of medical intervention you're describing: https://en.m.wikipedia.org/wiki/Fa%27afafine https://en.m.wik

This already exists in Samoan culture outside the kind of medical intervention you're describing: https://en.m.wikipedia.org/wiki/Fa%27afafine https://en.m.wikipedia.org/wiki/Fa%27afafine But it's not really viewed as a "choice." Samoan society is just arranged differently to reflect the more variable realities of gender.