My 2019 Silverado 5.3L is doing the same. I get 1500 miles and my oil pressure low light comes on, I check the dip stick and I'm already down 2 to 3 qts low. I brought it up to our dealership last month when I went in for yet another oil change and they had me log my readings every time I filled up with gas. Took it back last week and they did an oil consumption test on it and low and behold they told me it was consuming oil. Hmmm. They are keeping the truck until they can find out how and where the oil may be going. I overheard another consumer telling the service department about the exact same issue on his 2019.