That would certainly explain much of why Shadow's story is so beloved; specifically isolated from the rest of Sonic, including it being a rehash of Chaos's story in Adventure 1, it's actually well done. Rouge could've been the one to trigger Shadow's true memories and shit would've still worked.\

So if you only really care about Shadow The New Guy and are fixated on his arc the most, there's a decent chance you'll miss everything off about Adventure 2's story because those things simply aren't that obtrusive to the Shadow part.\