I can imagine transwomen into the context of the Handmaid's Tale tbh.
If they passed well enough, and were well connected enough, why couldn't they be wives? I could easily imagine a commander taking an attractive transwoman as his "infertile" wife (may or may not be actually infertile, but no babies in any case) and then getting a handmaid to provide the offspring.
Margaret Atwood said that everything that happened in the Handmaid's Tale had already happened somewhere at sometime, and its not a stretch to imaging a TWAW alpha male engaging a surrogate for him and his transwife. Religious males are famously flexible as long as their own status is intact.
They wouldn't be handmaids though and fertile transmen would be sent to the Red Centre because at the end of the day, patriarchal cultures are shit hot at correctly identifying sex.