Oh well there you go, I have never encountered a C152 with a cruise prop. Happy to be corrected.
As to checking the oil, the smooth acceleration might work with a C152, but are you going to rely on that when you move up to a higher performance aircraft? Would you try that with a Baron? (I don't fly Baron's, just a type that sprung to mind). It's just a small, simple habit we try to build in the early stages for when people progress onto more advanced aircraft. Same as checking Gear down on downwind. I hope it's there on C152 and if it's not, there is bugger all I can do about it. Just another habit so people will hopefully do it the first time they fly a retrac.
Agree with you though, nothing beats good knowledge of your aircaft. Do whatever the Flight Manual says.