An iPhone 6C or iPhone 7C has been rumored for a very long time now. When the iPhone 6S came out everyone thought Apple was sure to release a cheaper iPhone model which would be called the “iPhone 6C.” Since the iPhone 5C came out during the the iPhone 5S launch. Which made all of us sure that they would release a new iPhone C model.
To allow Apple to make a more affordable iPhone and make it some-what spec it will have to make some compromises.
Rumors from sites like MacRumors.com, suggests that Apple will put the A9 chip from the iPhone 6S in to the 6C. But, in order for that to happen they’ll need to add a smaller screen and not include 3D Touch and Touch ID. Which will make the cost of the 6C affordable to more consumers.
A lot of rumors do suggests that the iPhone 6C will have an 4-inch screen to make up the cost of the iPhone. Same with the 3D Touch and Touch ID, They won’t include them.
So I would say that it’s very likely to see a smaller screen on an iPhone again.