Being an old fart, I've read a lot over the years and this is what I've found. When they make the engine blocks, they high pressure wash the block before assembly, but they also said not every bit of waste gets removed. So I usually change the oil and filter at the 2,500 mile and then every 15k per my manual or once per year, which ever comes first.

But then after reading a lot over the years and talking to many truckers, I added a 2 micron by pass filter setup. Doing a sample once per year with BlackStone out of Indiana, I will change my filter every 5k using enough new oil to refill the new filter keeping the oil pan level at proper level. Doing this, I keep the same oil until it heads towards the outer perimeters of the sample then change everything. (many truckers do this without any mechanical problems)

Last full oil change was after 80k (I couldn't take it any more and had time on my hands) but still within the proper oil specification limits. Truck runs great.

(Also, as mentioned before, they pressure wash before assembling, but I still installed a coolant by pass filter which removes the casting materials imbedded in the casting from the coolant side and my water pump is still original and running great. Just an FYI.)