About 6 months ago, the dealer called and said GM could build the truck I ordered if I deleted the heated seats, head up display, adaptive cruise control, advanced navigation package and a couple of other options. He said some, but not all could be added later when parts became available. The head up display, adaptive cruise control, and a couple of others which I really want, could not be retrofitted however so I declined.
The dealer said the the truck can now be built and / or retrofitted, with ALL the options I want. I paid a $100 fee to "reserve" the truck but it is refundable if I don't like what is delivered. I'm keeping my fingers crossed.