The 2020 puck specifications are different than 2019 GM trucks. Their short bed versions have beds which are longer than previous short beds. Couple this with the hitch now being 3-4 inches behind the rear axle and maybe GM is looking at the marketplace and have designed their short bed truck for fifth wheel use without a slider. B&W has part numbers for the 2020 trucks which use the pucks. There are many hitches that would probably work if you used the gooseneck ball. I would be concerned regarding the 4" of offset of the Andersen added to the 4" rear offset of the truck ball. I would research it pretty hard before I jumped.