^^^THIS^^^, 125%
a friend of mine is a retired chevy dealer, sold out several years ago. when telling him about my situation, not in the same words but that's exactly what he said.
i have mine back and took it to the Chesapeake Friday with boat in tow. i swear it runs better now than it did the first 5600 miles before the main bearings let go; those bearings were junk from mile 0 and it showed in engine performance. when i bought the truck i didn't feel like it ran as good as the last 6.2 i had and I attributed it to change in tech or whatever, didn't know. and, i wasn't aware of the issues they were having at the time. this engine runs as good if not better than the last 6.2 truck i had.
i've moved forward with retaining an attorney and going for lemon law; the attorney indicated i have an excellent case and would highly likely get some sort of relief (trade for new one of same value when this one was new, cash payment of difference between value when it went down vs new value, or complete buyback). it was at the dealership for 1 week shy of 2 months. all it takes in WV is for the vehicle to be for service over 30 days in a one year span. so, screw GM, the prix can replace it with a new babymax.
hope the dude that resurrected this thread has better luck on timely repairs than i did.