I have this same issue, 2019 Silverado RST Crew Cab, had it since day one of picking the truck up. First time in for service they said it was all fixed after a day, but it all remained. Finally after going back and forth with Dealer service and having another dealer do a ride a long to verify the sounds, my dealership service took the truck in again to fix it. This time they had the truck for 81 days. After day 30 I contacted GM for Lemon Law and worked with their Sr. Advisor. On day 50 of the truck being in the shop, GM agreed to start a buyback, in which I told them I was wanting a refund and not another truck as I was thinking it would have the same issues (as you guys have shown on here, I was thinking correctly). After about another 1-2 weeks going back and forth with GM they said they would do a MSRP to MSRP swap, I again said no I would like a refund. So now I'm in the process of this with the lawyers and pursuing a refund under Lemon Law. Under my state's lemon law, after 30 days of vehicle in for service customer can request a refund or replacement, customer's choosing.
I had no idea of the statement from GM that you guys showed on here that states to stop fixing until a solution is out. After learning this I went to GM and got my build sheet and sure enough, mine has the SU4 - AXLE FRT