I thought they were, but I wasnt sure about things like VATS, tow/haul, tap shifter, gauges, and so on. Sometimes something as simple as just an a/c turn on can drive you nuts.
GM is extremely consistent; they never really change things unless they HAVE to. Even the databus messages and structuring is mostly the same, as long as you're talking about the same "era". IE the GMLAN messages for tach, speedo, crank request, etc on a 2010 Camaro are the same as an 07.5+ pickups etc.
Thats why 03-07 shares an identical electrical system (regardless of gas, diesel, LB7, lly, lbz), 11-14 LMM LML shares the same system, SUV's and pickups share the same system, etc...