It was my understanding the cyl head replacement era was due to the errant “cyl misfire” codes due to the coolant jacket design which caused the valve seats to shift on some heads which has been corrected (discussion at the engine plant actually) More times than not you wouldn’t have even noticed if the CEL didn’t aluminate. Now the “ticking noise”.... rocker arms. Still see this and if you catch it in time you can even get away without changing out the cam. One other point of interest I’ve noted. Light use excessive idle time vehicles seem to come in at earlier mileage with rocker issues. No solid scientific data on this.... just a pattern I’ve noted at work.

Personally it sounds like Mr Class Action is trying to find a loophole to get his s**t for free.