It’s planned in two possible forms:
a) maybe through optional magic/potion–based content that you can completely skip ,
b) as a part of the story later on — also optional and definitely not happening anytime soon, since the plot needs to develop much further before we get there.
The theme of life/continuation of the species is one of the narrative threads of this world, and it will be revealed gradually. The MC being the only man in this world isn’t just because it’s an erotic game :p — it’s actually an important part of the lore and the main storyline