My truck has given me nothing but trouble (threw another 2262 today) but the oil change monitoring system has been one of the only things that functions "normally". I get the oil changed about every 5k and only seen the oil change message once, when the dealership didn't reset it. That time it was exactly 7,500 miles.

I read a thread somewhere that said the ECM is monitoring the amount of time spent in regen and the amount of idle time as the primary data. It's trying to guess how badly the oil is diluted by fuel with a goal of not more than 5%. I don't have direct knowledge - just passing on info I read elsewhere.