I got to be honest, I'm not too enthusiastic about the idea of Sesshoumaru and Rin if that's the case. Always came off like fanfic trash to me.
I'm not convinced a sequel to this was necessary, but we'll see. Honestly, I was always fairly mixed on the original Inuyasha. I thought the show got repetitive and slow after a while and just started spinning its wheels. The climax of Band of Seven for example. It was this big epic long-spanning arc, but it felt like the ending went nowhere. Just same **** different day. So the anime actually had to just end in the MIDDLE OF THE STORY just so they could let Takahashi actually finish and figure out an actual ending.
Just for example, Naraku got really boring as a villain after a while. Inuyasha and Kagome as a relationship was badly written and what I mean by that it seems like every time they took two steps forward, they took five steps back. Just for example, the binding spell where she makes him sit. I think a pretty amazing progression would've been to do away with it at some point. I think they even make it a plot point in one of the movies and the binding necklace gets broken apart, only for it to get put back together and placed on his neck again. I realize the movies are filler and they can't alter the status quo of the regular series, but that felt like a cruel move for Kagome to do that. It felt like a violation of trust.
Also, here's another thing that never sat well with me. We meet Kouga after he's just slaughtered a whole village of innocent humans. Then the show ends up making Kouga a hero. And the fact that he's introduced having slaughtered a whole village of humans is never brought up ever again. IMHO that's bad writing and storytelling.