This scares me. Hasn’t this been an issue going back to 2009? Is there a way to drive or service to avoid this problem, or is it the luck of the draw? I don’t understand how some HEMI’s have zero issues and some folks get 250,000+ miles with nothing but air filter and oil changes and spark plugs, and others get absolutely screwed before 50k. What gives?
The lifters were updated in 2015, and the issue has been significantly reduced, but that doesn't mean it never happens anymore. the issue isn't driven just by the lifters themselves, but the actual design of the motor plays a part as well. I'm not sure if the OP idles a lot, but apparently that can be a contributing factor.
Failure vs mileage follow a bell curve, some will fail early, some will fail late, and the vast majority somewhere in the middle. You never hear from those people in the middle because they have no reason to ever think about the condition of their lifters or cams. The subset of people that experience early failures are going to be much louder, and have far more presence on forums looking for information about their failed component.
Try not to let it make you nervous, just follow the maintenance intervals, and don't let your truck idle for 5 hours a day. Statistically, you are far more likely to land on your feet than your a**