Not necessary, I remember when I was in japan reading a manga about a magical girl using mahjong tiles to transform or something. Was kinda weird. But could be a show like that.
I mean, one of the premise of sakiverse (aside that panties are non-existent) is that mahjong is a widely popular game, so by that logic, wouldn't be strange that they make a lot of mahjong related show and that it's popular with the kids. ^^