Different GM truck: that's their conventional (non-hybrid) pickup.
Poking around online, it looks like the original hybrid pickup truck that I worked on was discontinued in 2007, and the second version of the hybrid pickup truck, with a somewhat different design, was discontinued in 2013. I can't find any current hybrid pickup offerings, so it looks like they dropped that capability, and with it the higher capacity 110V system.
Where are you getting that from? I don't see any power figure quoted in the article.
As it happens, I worked on that truck while I was an engineer at GM. Its 110V outlets could provide up to 2400 Watts.