I don't think anyone was trying to say 2B was properly seeded (strength-wise) as a 1-seed just because she exceeded all expectations. Honestly, she should have been a 2-seed (not in terms of strength, though).
Yeah, the surprise was that she wasn't hilariously bad fodder. She was still overseeded but beating Ness was way above what was expected from her (let alone her score against Bowser)