This " expert" doesn't make sense to me since I consider 3c to be kinky hair since kinky means tightly curled. Anyway people have altered these "descriptions" over time because of additions to types and probably their need to put in their two cents. Originally 4a was a range and not just an exact size. It went pencil to coffee stir. My hair in my nape becomes straight when soaking wet.
"More people would learn from their mistakes if they weren't so busy denying them." - Harold J. Smith.