I think it still aligns with the plot though? since the very first mention of the Azure Wind Society, it opened up the possibility that the Cheon family might have already lost their power to this mysterious power since the death of the grandfather. Also the grandfather seems to not actually hate his daughter but instead there was some mystery in it and Kim Muhyuk's parent hasnt really been touched on so thats free real estate to expend the story on but at the same time still seems natural? Only me?