Nope, sorry. The team's artistic vision for the game includes trans NPCs; you can use the sliders to set the amount of them that's generated very low, but you can't remove them completely. This is a failsafe so that if we write in a new character archetype that requires the assigned character to be transgender -- say, a mini arc about a character coming to terms with their identity, or something -- the game for sure has an NPC ready to go for it instead of having to retcon an already-existing one to fit that mold.
Consider: would you rather have like ten NPCs already be trans so you can just avoid them if you're not into that, or have a character you're actively involved with get retconned as trans in a game update?
