Why not just state that no gender can be completely removed from the game instead of saying trans can't be removed from the game to keep things simple?
It doesn't really make sense to have a specific archetype that's just one gender when, as far as I can recall, all the archetypes are written to be fluid in genders. Is there a specific archetype that's solely one gender in the game so far? It'd seem strange for there to be a mini arch for just one archetype that specifically NEEDS a trans person.