I don't think they had moved on from the Wii totally, rather it remained sitting under the TV for occasional Wii Sports and Mario Kart in many a household. So it was already there for when something did come along. That something required no fancy online or graphics and was for kids, so unlike other multiplatform games there was no real advantage to getting it on another console, so the console with the bigger install base sold more. Contrast this to where people don't already have (and mostly don't want) the Wii U, and can get Skylanders already on another or past gen console.
I don't have any personal interest in this if it's supposed to be like Skylanders, since that's essentially targeted at kids. So for me, I'm looking at it totally from a success perspective. How popular it becomes will influence console sales, which in turn could bring in developer support.