I don't have a crystal ball or anything but I would suspect that Mazda will eventually come out with a new 6 cylinder engine to run in the CX-9, and maybe the Mazda6. Much like the CX-5 first only came with the 2.0 only to have the 2.5 added later. My guess is that mazda wanted to get the redesigned CX-9 to market sooner rather then later to try and capture some of the market share for 3 row SUV's away from the likes of Honda, Toyota, ford and chevy. There 6 cylinder just isn't ready yet. I don't know, maybe they aren't even working on a new skyactive 6 so I could be completely wrong, but it would surprise me if in a year or two you start hearing rumors of a new 6 cylinder engine to go into redesigned cars and SUV's. I also suspect the next CX-5 will get the 2.5T and perhaps a Mazdaspeed3 is on the horizon as well.