Poll results: the old style Edge Panels won't be missed all that much6
Nowadays, the Edge phones are curved on both sides, but have shallower curves, which can't house a full secondary panel on their own. The panels are pulled out when the user swipes in from a specific "handle" point either on the left or the right of the screen. From then on, a small drawer comes out, blurring the main screen content, and we get access to widget-like controls for Favorite Apps, Favorite Contacts, Weather, Tools (ruler, flashlight, etc.). So we do have the on-demand panels, but to use them, we need to sacrifice our view of whatever we are doing with the phone right now.
On the original Note Edge, the panels were thin slits of actionable widgets, which resided on the very arc of the display. Due to their size, they were capable of showing limited amounts of data, but on the flip side, they were always visible. If you were to enter an app that runs in fullscreen, the Edge Panel would automatically retract, but swiping in from any point of the right side of the display would call it back out. No blurring, no obstruction, you could have both the main display content and Edge Panels displayed on-screen, and use both.