Modern engines are sealed in a certain way.
There are lab tests show that storage time has little to do with engine oil quality, especially with modern synthetic polymer and additives technologies.
2 years period is common to German cars, whereas 3 years is acceptable.
I know a few friends who change their oils every 3 years in their 1960s cars.
However most ppl in HK will tell u to change regularly because it is what they had been doing for years but car condition is shttier than a 50 yrs old.