it's good to ask - there are instances where it's a dire necessity like newer Subaru EJ turbo engines that are problematic regarding oil supply. and if you're towing huge loads often, racing, living in sub-saharan africa, or the arctic circle, or you want to make 1,000,000 miles - good to rethink that/ask about oil.
but for average daily driver Subarus at least the discussion about ends there - follow the owners manual.
as much as i'd like to herald myself as the subaru-shiznit-of oil changing engine longevity and the miles i get out of them, it's got nothing to do with my random selection of on-sale oil and filters, i simply know how to read...the owners manual.
for the person that touts a brand or method that gets them 300,000 miles and a clean engine - there's 100 guys buying whatever is on sale and getting the same results....they just don't talk about it. luckily - this forum has more of the "100" guys in it....some forums it's the other way 'round.