No, you're thinking about the navigation controller, which is basically a deep stack of views that you can travel between. The side navigation they're talking

No, you're thinking about the navigation controller, which is basically a deep stack of views that you can travel between. The side navigation they're talking about is a "global" view that sits below your normal stack, that you can get to at any time. So instead of backing out to the top of the stack and selecting "read messages", now you can just gesture-swipe to the side and access the "main menu" directly from anywhere.