I also heard somewhere they planned a metroid game for the wii u, but the developers (retro studios iirc) said if they started now, it would take about three years and by then the new console would be out for sure. Hopefully they'll learn how to market their next system properly.
At least we know Nintendo does care about their franchises
I hope it makes a return for the nx becuase Wii U support is likely to drop in 2 years