While I'm inclined to agree, I'm not entirely convinced. There isn't a blurb that separates mechanics from fluff. The best way to state it would be that it isn't in the "Class Features" section. There's still too much leeway with that explanation. A dragon is a magical creature but it's breath weapon is not magical. A monk isn't inherently magical but Ki is. I'd definitely rule that Ki is nonmagical, though. I just don't know how I'd go about completely changing someone's mind that it isn't.