I don't think that's true? The goal of vouch isn't to say "@linus_torvalds is Linus Torvalds" it's to say "@linus_torvalds is a legitimate contributor an not an AI slopper/spammer". It's not vouching for their real world identity, or that they're a good person, or that they'll never add malware to their repositories. It's just vouching for the most basic level of "when this person puts out a PR it's not AI slop".