Kalos is directly North of Unova.

On the official maps not only do the rivers match up but even the shape and shading on the clouds do. You could dismiss the rivers as maybe just a coinsidence but not the clouds as well.

So does this mean we'll get to visit a cut down version of Unova in 3D either in post E4 or in X2/Y2?

One thing it definitely shows is that the Kalos region will be larger than the Unova region was.