If there's no iPad Air 3, I could see them dropping the price down about 50 dollars if Apple is looking to be a little charitable this coming holiday season.
However, I don't see that very likely, but I wouldn't be shocked if they knock the price down by a hair in order to look better — even if the Air 2 is a very good machine and will be for years to come.
I think there will be an Air 3, but it'll just be a chip upgrade and that's probably literally it. It'll be like the Mini 3 last year in my opinion, except that was even worse of an "upgrade" and was just Touch ID and a color addition.