But would you really call Mago's end a "cancellation"? It seems more like the author wants to go in a different direction, hence the sequel.
And that cover is making me want to reread Neuro again. I'm so glad Matsui's back, it only took him 3 years. T__T
It sounds like the sequel will only be the conclusion of the Aoi Rasen-Jiu Saishuu Kessen (Aoi Spiral Castle's Final Battle) Arc. For whatever reason Shueisha is treating the Jump NEXT chapters as a sequel, akin to 21st Century Boys I suppose. Sasaki even felt the need to specify that the Jump NEXT chapters would be made available in English. It seems to me like a Shaman King situation, rankings could no longer justify serialization, the story was drawing to a close anyway, so they canceled serialization in Jump in favor of serializing the last volume in Jump NEXT.
I think that when compiled the Jump NEXT volume will not be numbered, but simply titled Nurarihyon no Maho: Aoi Rasen-Jiu Saishuu Kessen. Just a guess, but that is what I think they mean when they call it a sequel. It is going to be treated like Shin Prince of Tennis or 21st Century Boys, but since there will only be a single volume, they won't even give it a number. I've never seen a single volume series numbered.
Is Mago getting a sequel? Or am just getting my hopes up?
You are getting your hopes up. The three Jump NEXT chapters are being referred to as a sequel by Shueisha.