Yup, and the confusing part is that most manufacturers of those 22 inch roll-a-boards claim vociferously that their bags can be carried on, but sometimes they're actually marginally over the limits (22.2 inches tall, or worse, just a bit wider than they're supposed to be so they won't even fit through the template at the x-ray machine). Furthermore, even for those bags that are "in spec" empty, they can very quickly get "out of spec" if you stuff them to any extent, since they're soft-sided.
However, even all that can be moot, since if there isn't enough room to store your bag safely, then it will be checked anyway. I've even seen times when FAs tried to check BOTH bags carried on by a passenger because there wasn't room for either. (Typically you can convince them to find a place for the smaller one, but if they're both the same size then you could truly be out of luck; FAA requirements for safely storing bags trump whatever "right" you might have to carry-on a bag, and you're technically not allow to argue with FAs about it, even to point out that other passengers probably have stored two bags in the overheads...)