Maybe GT is "Great Truck" ?
Grand Touring in the sense of long trips and higher speeds is exactly what I want in a vehicle. I want to be able to take long road trips in comfort and have plenty of power on tap for interstate passing, room for luggage, etc. My Ram is almost always our road trip vehicle (ALMOST because if the destination has parking concerns where the Ram won't fit, well, duh). What I'd like in an actual Laramie GT package:
A slight lowering/leveling kit. Maybe 2"/4" or so? Retain the ride, increase handling, maybe a little bump in fuel economy (fuel economy = range and the more range you have the more options you have). A full time 4wd system, rear biased, that handles snow, heavy rain, etc for when you get caught in the mess on your trip.
Larger gas tank. Again, range = options = freedom.
HUD. It's one of my favorite features on my Camaro. I like having speed and basic info right in my eyeline as I drive, especially if it's...spirited.
Factory bed rug and hard cover that's lockable and water-tight. Touring involves luggage, after all. GT isn't about hauling mulch.
All season performance tires. Of course you're going to lose some off road capability. It's grand touring, not mud bogging.
The Rebel GT concept could be more of the luxury overlanding build.