Is it really the first generation though? The screen is obviously 1st gen for Apple, but you'd think the rest of it is not: OS, battery, camera.
The previously released iPhone Air looks very similar to the fold, and I believe it even used the Apple modem C1 generation.
It'll be interesting to see how many/how quickly apps adopt the UI that lets you make the most of the foldable screen. If it doesn't sell in big numbers app developers might not feel the need to and the user experience will be subpar. ...but I suspect it will.
There is a lot of software support needed to make this work great. So first generation of all that for sure.
Well, the screen is the new/groundbreaking part!
Considering the most important parts of the Duo are the screen and the hinge, yes it's a first generation device.