Perhaps it's just a selected few who have this issue with GM vehicles. I've owned nothing but GM for the past 30 years and none of them have ever used more than 1/4 of a quart between oil changes...There are some anti-GM people on this board who would like everyone to believe that all GM's drink oil. It just ain't so. I've had numerous 5.7's, 6.2's, 5.3's, 5.0's, 4.3's, a 6.2 Diesel and whatever that 5cyl is in the wife's Hummer and none of them consumed any material amount of oil even if run to 200k. Can't speak to the 8.1 as I've never owned one.
At least GM jumped on the self-imposed recall. Another brand had to burn a few garages down before they addressed their cruise control problem.