Looks like I am one of the lucky ones. My 2020 TB 6.2 had number 6 lifter go out two weeks ago, 500 miles from home in Orlando, FL. Limped 10 miles to the nearest Chevrolet dealership and was blessed the fleet mechanic was standing by the service advisor. My truck has 12K on it so they replaced all the lifters on one side, if I would have had less than 8K they would have replaced all of them. So now I have a ticking time bomb on the other 4 cylinders, thanks Chevrolet. I have an appt with my local dealer in 3 weeks and will see if there is anything they can do about the other ones. They got me on the road in 24 hrs, so thankful for that.
The fleet mechanic told me that the original manufacturer of the lifters were just bad. He was replacing ones that had already been replaced, it was about all he did in 2020/2021. Chevrolet has a new supplier (not sure when that happened) but these new ones are holding up. Hopefully one day they will do a full recall on these. I was pretty lucky I have the 6.2 since they had those in stock. Lifters on the 5.3 were out of stock and had been backordered for quite a while.