When using air blasts, air wild talents, or composite blasts that include air, double the blast’s effective range. This effect applies after altering the range due to effects such as the extended range infusion. This doubles only the blast’s effective range, not the area of effect for infusions like cloud and cyclone.
You use your element’s power to instantly move 30 feet in any direction (even straight up), manifest a kinetic blade, and attack once. ...
I don't think blade rush's instant movement is a range of a blast exactly. It'd be a totally reasonable house rule though.
It's completely vague. My guess is that air's reach was not intended to double the range of blade rush, but the text we have doesn't actually forbid it. And it doesn't seem overpowered to allow them to interact.
The point against would be that "range" was in reference to a ranged attack, or the range of a spell. And bladed rush is pretty obviously based on the bladed dash spell that has a range of personal. So, the movement would be more like the area of effect than the "range".
[Side note: super weird, I had the same realization at almost the same time as your time stamp.]
Personally, I love the idea of using Air’s Reach with Blade Rush. On a Kinetic Knight, it gives you a ranged attack equivalent at the expense of wasting Air’s Reach — I’m pretty sure it will work with nothing else you can get, but I still love it. For maximum fun, grab Air Cushion and Blade Rush up into the air, then land safely wherever you want.
RAW are unclear if AR & BR work together, but I certainly think they should. If doubling the range of other all other air attacks is okay, why not Blade Rush?