an Air 3 is just around the corner that is going to fill that $499 price gap.
Umm the new 9.7 inch iPad Pro IS the "Air 3" the difference is they just changed the names from Air To Pro because the word "Pro" sounds so so much more appealing and attention grabbing to people and will be more of a money earner to Apple then the word "Air" just like they changed the names from the iPad 4 to the iPad "Air" couple years ago!
So there won't be a iPad "Air" 3 as it IS the new 9.7 inch iPad Pro, basically just think of the new 9.7 Pro is the "Air 3"!!