Class action suits are started by law firms that can make a case to extract settlement $$ from large corporations. They are designed to pay the law firm fees, not the claimants. You'll see pittance paid in settlement funds.
Government agency actions, like EPA, that's a different deal. Then the company has to make things "right" or face further action, fines etc.
As a dealer, it's not criminal to fix a truck and sell it. If it had a leaking oil cooler, and that was repaired, there is no reason to disclose that normal repair work.
My theory - the crankshaft cannot tolerate twisting, caused by restriction in the exhaust stroke. The restriction either from the SCR/DEF or turbo somehow. I don't think it's the DPF. The crank "twist" causes bending, bearing load failure and in the case above outright cracking.
This engine issue is NOT limited to the Ecodiesel. It's happened with Range Rover too. The Td6's are splitting cranks and throwing rods and bearings too.
I took the advice of the diesel shop and did a delete. Unfortunately not sure what else can be done with the earlier engines. Drive longer distances if possible. Keep fresh DEF in there. And pray