I agree and share your skepticism, especially when it comes from a dealer, but there are some cases where Subaru REQUIRES you to change @ 3000 miles for first oil change. Specifically, I'm referencing the 3.6l 6 cylinder engines, after this change it follows 7.5k OCI. I'm curious about the justification. The 2.5 NA Forester required a first oil change at 3k miles but was changed in the manual with a revision in 2012.
Would anyone have data (MSDS) about current Idemitsu Subaru 5w-30 oil?
Best I could find is a revision in March 2012, which I don't know is the same as supplied to Subaru.
CATERHAM from BITOG, has information in his post but conflicts with above.
It is however from a revision in Aug 2011.