Propaganda indeed. Chevy has been using this test for years to try and "brain wash" the "unwashed masses" into believing that a rigid frame is better. Here's a video from 5 years ago (2011) when they claimed the same thing. No one cared back then, and 5 years later no one still cares:
https://www.youtube.com/watch?v=TKMQjm7i2Jw
Thing is... frame twist is something you actually want in a truck. It keeps the tires on the ground, keeps traction in rough situations, and prevents damage to the frame. You don't want a rigid frame when doing things like snow plowing. How many chevy's you see plowing snow? Hardly any. The frames CRACK big time on the chevy's (and dodge too). Also, how many millions of trucks have been sold by Ford and how many cracked or broken frames, or even cracked beds, do you hear of. Finally, no moron would ever park their truck on terrain like that or try to unload stuff. And honestly, I don't even know if chevy could reach terrain that rough. Would probably crack their frame down before it got there especially if the truck bed was loaded with heavy stuff.