Don't know who told you they are supposed to be in contact, but not in my understanding. That's a sign of torsion bar fatigue or maladjustment, far as I know.
I mean think about it, it's a BUMP STOP to limit travel, not a shock absorber. Why would it be in contact all the time, totally infringing on range of motion?
My wife's Tahoe was new to us and never in contact, even as it approached 200k mi. Never took a wrench to her '05 k1500 Z71, here's how it sat -
I put the non Z71 factory bumpstops on my Sub, after the same Rancho leveling keys, with a little bit of crank for a level height, with tired rear springs and 2" rear spring spacers, with about 300# of gear / platform / drawers in the back all the time.
My Sub when bought used with 116k mi -
Side by side of standard 'beehive' stops and chewed up Z71, when I put fresh in my Sub