If the idea is to eventually focus on 2 iPad's on;y, with neither being the mini, wouldn't introducing the "Pro" alongside an iPad Air 3 be more logical? That way the new "Air" could fit into the price-point of the mini and the new "Pro" take over from where the "Air" was.
Focus makes me think different lines: MacBook, iMac and MacPro, those are three very different lines. iPhone 6, 6 Plus, iPod Touch, iPad Air, iPad mini, iPad Pro. Those are all similar lines, very very similar focus. Drastic differences when you compare the use of the smallest to the largest, but very similar products. Add a smaller one, add a larger one, take one out of the middle, and you're not drastically (even minority) changing the focus.
Gary