Mark Gurman, with more information on the iPhone 5se:

First, we are told that there are different prototypes of the device floating around Apple’s campus: some with the A8 and M8 chips that we discussed in our previous report, and some with the iPhone 6s’s A9 and M9 processors. We’ve now learned that the iPhone 5se is more likely to include variants of the A9 and M9 chips instead of the A8 and M8 lines. […]

Lastly, we are told that the 5se will also likely see another boost over the 5s: a higher capacity. While the new device will likely start at a 16GB capacity to match the 5s, the secondary, higher capacity is said to be doubled from 32GB to 64GB.

At what point would Apple consider this device to be part of the iPhone 6-family rather than the iPhone 5?