From what I know, the edge has roughly the same engine block, but that's about it. CX-9 has different fuel injection system, different intake, different starter, different alternator, different a/c compressor, different ignition, different engine mapping, different shape of the engine bay (front inner structure is not shared). The mounting hardware likely would not fit right, the electrical socket/connector would not fit (if K&N has an altered mass air flow sensor which is what appears in the photo in that link in your post), tube may or may not be the right length and/or diameter, etc etc.
The CX-9 and the Edge don't even share the same hub&bearing because Mazda thinks the Edge bearings suck (sorry - that is my bias speaking)
In my opinion, this would not work. I could be wrong.