I understand that the official specs on the phone list two displays, but I was under the impression that from a physical hardware standpoint the entire thing is one LED display that is manufactured on a flexible plastic substrate and then installed underneath a curved piece of glass, and then the software in the phone divides the display up into two parts and can activate either one or both as needed.
But, since neither of us are actually involved in the manufacture of the phone, I don't think anyone can say for sure. It's certainly possible that there might physically be two displays under the glass screen, and it's possible that it may all be one piece.
Either way, arguing this is a moot point in relation to the actual topic of having the "edge" functionality on a normal phone. Again, I don't think anything precludes a normal phone from having the exact same features on it as the Edge, the only difference being that the edge toolbar would be flat if it were implemented on a normal phone.