https://www.gamespot.com/articles/sq.../1100-6465810/

I asked Yoshida if Square Enix would considering allowing more gender options for Hrothgar and Viera in the future, but it appears the studio wants to consider feedback first before making any announcements. Yoshida also said to GameSpot that, due in part to the high complexity and challenge of creating new races and balancing them, Hrothgar might be the final new race added to Final Fantasy XIV Online.
The missing genders might not be off the table just yet.