Someone else here had a theory which I agree with that they will be 13" and 15" MBPs, not MBAs, and there will be a 14" rMB in addition to current 12". Air line will disappear.
I don't disagree with your conclusion ... in this regard, at least, anything's possible.
Just for fun (or if you have several hours to kill) let me point you to a bizarre thread that wound up consuming nearly 60 pages before it became evident that a new MBA wasn't going to happen:
https://forums.macrumors.com/thread...esigned-retina-2014-2015-macbook-air.1656178/
Actually, I think the lack of forthcoming new hardware was pretty obvious to everyone except the thread starter some weeks before the thread's timely demise ... and I submit that the odds of a new MBA are about as great this time around.