Ahhh yes! The infamous GMT800 I.S.S. (Intermediate Steering Shaft) issue.
IIRC, first recall was to repack the spline with grease. That would tighten up the tolerance for a while and the knock would eventually return.
Second recall was to replace the shaft with a revised part. When didn’t work, back to repacking with grease.
The steering on my 2020 feels odd at times but overall performs well. I have the digital steering. Seems to have very, very light effort on center, possibly a quarter inch or so of play left and right off center, hard to tell. The odd part is that the truck tracks very well at all speeds. No wandering at all, tightens up nicely as speed increases. I have noticed a few instances of very slight knocking felt through the steering column. Approaching 1000 miles.