A6X, not A6. The A6 isn't meant to push a 2048x1536 display. Just remember that the iPad Mini is a smaller iPad 2 and the iPad Mini 2 will almost certainly be a smaller iPad 4. Any variation from that will be a real headache for developers because they'll have to do iPad 3-like adjustments where the GPU wasn't really enough to power the display at full resolution in games.
Yes, I know. I thought I typed an X.
My point still stands.