I just dug through everything I have on it from GM and they aren't showing the weight there yet either.
Ya, not a word yet on mass, I think the first edition SUT will be 7000 to 7500 lbs curb weight, as looking at the design, I think they made a massive effort to reduce mass, but that + or - 2200 lb battery pack makes it interesting. GM could come in slightly under 7000 lb, but I think that would take some amazing light weighting in the chassis.
On the lightweight side It is smaller than a typical crew cab pickup (both cab (interior) and box are smaller), it is a unibody, and it does have aluminum front suspension towers, and control arms, even the side crash beams look to be aluminum extruded pieces (lightweight and strong).
On the heavy side that monster battery pack, underside cladding, big tires and wheels, rock sliders, 4 wheel steer, 3 motors all add up. It could come in around 8000 lbs, but that to me would be disappointing.