My hypothesis is that they will bring back the smaller size once the larger sizes have been legitimized. If they had simply introduced different sizes, the comm

My hypothesis is that they will bring back the smaller size once the larger sizes have been legitimized. If they had simply introduced different sizes, the community might see the new (pixel) sizes as "alternative". Developers might be annoyed at having to support something other than the one-true-size-that-Jobs-left-us. Instead they dropped that one true size and made it clear that an iPhone now comes in multiple, larger sizes. These will now forever be canonical sizes, even when Apple continues the smaller size.