It's not a legal thing though. And I would think with an all new LAN architecture as these new trucks just came out with, that it couldn't be easily done. Sounds like more or less cost cutting combined with putting money in to other features.
Does yours have that trailering camera where it can more or less render the trailer invisible, so you can see what's actually behind the trailer? IF so, there's the money spent vs. auto up rear windows.
has the option to add it. i don't own an enclosed trailer though- and that'd be really the only benefit. im not going to mount a rear camera to my boat to see behind it while backing, so i wasn't too concerned about that option.