It's more manufacturing tolerances that come into play. And though we have gotten far better with accuracy and repeatability, we are far from perfect as an industry.
On our spring lines we go to great lengths to make sure our springs are consistent, broken in, and ready to go. However some manufacturers couldn't be bothered to care about how uneven or unmatched product is, and often times at the rate of production our lines face, that is what they get. As long as the parts bolt together they don't care.
I'm not quite sure of the connection and relevance of the "tolerance" argument. Generally there'd have to be a fairly severe out-of-tolerance condition to create early pre-mature wear and usually result in warranty claims somewhere down the road. These conditions would not be made better by early and more frequent oil changes.
I'm currently a quality & warranty engineer at a major Tier 1 automotive supplier that shipped just over $1B in automotive parts last year. Every customer we have has cleanliness requirements for incoming precision parts and this is monitored on a regular basis to ensure compliance. Subaru, as with the rest, also have additional secondary QA controls on supplier components prior to their engine assembly.
I'm not saying early and more frequent oil changes will hurt anything, unless the manufacturer did have special break-in additives (and there are a few that still do). I'm just saying this is more about folklore perpetuated on forums and makes everyone feel good, but is ultimately a waste of money.
But it goes to reason seeing that for most of us participating in these types of forums, the automobile has a strong emotional connection. So if you got the extra time and money...go for it!