The male genitalia, female genitalia, and and breasts were made as form traits so that they could one day be chosen independently from one another. The plan was to allow a potion that would allow the player to customize these aspects, at least when in their base form. This wouldn't have any mechanical difference to gameplay, and these changes would likely be contradicted by a number of transformation text passages, so ultimately it would just be a personal roleplay mechanic more than anything else and hasn't been prioritized.