Well that didn't take long, GM is dumping the 3.0 current version for a newer one. Main cause seems to be long crank times and having to drop the transmission to replace the timing belt. Not a lot of available info yet but it's a start. https://pickuptrucktalk.com/2022/04/replaced-already-new-gm-3-0l-duramax-diesel-lz0-coming/
Looks like the 2.8 is dead too.
Looks like the 2.8 is dead too.