I try not to consider things in terms of absolutes, so to answer your direct question: yes, I am pretty comfortable believing the vast majority of such links wo

I try not to consider things in terms of absolutes, so to answer your direct question: yes, I am pretty comfortable believing the vast majority of such links would be substantially factual. Google already does this, I don't see the issue with it hypothetically happening on YouTube. If you search for a well-known person, place or thing, you'll be presented with information aggregated from trustworthy sources. Can they be wrong? Sure, and it happens. It's not sinister. It sounds like you're envisioning someone manually tagging things. That would be odd and suboptimal. Instead, just tag helpful Wikipedia pages about the broad scientific consensus of things on relevant videos.