I wonder if he counted "like" or various other 4 letter disfluencies?!?
Like, you know, some so-called disfluencies are really fadfluencies that, you know, replace verbal insecurities with words that, like, bond and identify the budding ingroup i.e. the new breed.
And there are disfluencies and there are disfluencies.
Disfluencies are mostly pauses to maintain a verbal continuity until the sub-servo-brain finds the appropriate word of meaning.
Children pause and use fill words because they have a small store of words that can be used to convey their intended meaning.
Old folks pause and often say "um" because their mental cabinets are overfilled and many words must be rejected before finding the one that can properly convey their intended meaning.