100 chapters and the other 2 concubines haven't been shown yet

Meh. If they're irrelevant to the plot rn than I'd rather they not be in it at all than have some cheap filler episode just to introduce a character you won't be using for another 2-3 seasons.

Oh wait...either I didn't know there were 2 left or completely forgot. I'm with @Peachybxx. I'm kinda meh about it too, but I am curious as to if or when they will make an appearance. If you hadn't mentioned them, I wouldn't have thought of them. Lol