Programming the automatic transmission shift points is, like most aspects of configuring a car design, is an exercise in compromise. It would have been easy for Mazda to make the transmission to be more eager to shift up or down based upon subtle clues from the accelerator pedal but then you get a transmission that feels spastic, always changing gears at the wrong time, dropping down a gear and revving higher when the driver is just trying to cruise along in traffic and shifting into too high of a gear through a corner so it must then drop down again to accelerate out. Thankfully, the CX-5 does not lean towards this nature.
I think Mazda hit the right balance, when you want to accelerate you signal it by giving the pedal a good press. Otherwise it holds a higher gear and assumes you just want to maintain your current momentum. It is different from most other automatics but it doesn't take long to learn how to adjust so the car does what you intend. Just don't be shy with your right foot when you know you want to accelerate. I find that pushing the pedal down to a moderate level all at once will effect a gear change immediately while gradually easing the pedal to the same point will not cause any downshift. And I like the way the car automatically shifts to lower gears when slowing down. This often leaves the transmission in the perfect gear to ease on the accelerator out of the corner without needing to downshift further. But if you know you want a fast exit, just use the accelerator to tell it as much and it will almost seamlessly drop down another gear (or two depending upon your input). It doesn't hesitate for but a split second once you learn how to "talk" to it.
My CX-5 returns really excellent mileage and I don't baby the accelerator when I need to reach a new speed. Actually, I think I generally use less fuel when I accelerate at a higher rpm, more quickly, for a shorter distance compared to easing it to the same higher speed using lower rpm's and a higher gear over a longer distance. Of course flooring it and taking it all the way to redline will burn more fuel than either method. Moderation is key. In this sort of situation when the driver gradually eases on the accelerator and the transmission does not shift down, I do not believe it's because it's programmed to save fuel so much but, rather, the programming is conservative to avoid unwanted and awkward downshifts. Moving the pedal decisively will achieve the desired result.
I do not have a good feel whether the behavior I've observed is tied to a transmission that "learns" a drivers habits or not because I've never disconnected the battery to see if this would clear any potential "learning" and change the shift behavior. My guess is I could get in any 2.0L CX-5 and it would behave similarly.