Well, now we hear it straight from the horse's mouth.
With today's debut of the 2020 Silverado HD in the 2500/3500 weight class at the Flint Michigan Truck Assembly Plant, Scott Dammon, GM's Lead Development Engineer for the HD truck platform, explained why GM switched the trailer brake controller from the left hand side of the steering wheel wheel to the right hand side.
Scott Dammon, Lead Development Engineer, General Motors wrote:
"Changes... a BIG ONE is the Trailer Brake Controller is right here to the right. We heard from our customers a lot. They didn't love it over here on the left... you know... left hand on the steering wheel and they can easily control the gain on the trailer."
You can see Scott Dammon of GM say this yourself at minute 19:54 to 20:15 on this TFLTruck video linked below:
https://www.youtube.com/watch?v=bLq5MZnlyVc
https://www.youtube.com/watch?v=bLq5MZnlyVc
