Yepp! If that option hits later HC models maybe the 2015 can be updated. You know like McLaren and Koenigsegg do for ....... n/m
Having some experience on the early Challengers and adding steering wheel controls, there are a few things involved. The clockspring that sits behind the wheel and passes the signals, the harness in the wheel itself and the PCM needing to be programmed for the switches. ( sales codes added ). And when those are added, it actually acts like it's been wired differently.
I guess the factory can add whatever, but to add to a car without the options can be tricky