He's playing [b]over the top of the original drums[/b]. So for there to be a point, he has to do wibbly stuff, add flavour to it. I bet he'd wouldn't ever say or claim or think that this is how the drum part should actually be played on Thriller, or a cover of Thriller, by anyone.
It's no different to any other musician asked to improvise or play around the groove of an existing song, where the instrument said musician is playing is already in the song. As bassists, what would you do? You'd wibble about all over the tune, probably with some quite busy licks, to justify doing the exercise in the first place. You wouldn't play the bass line, because it's already there. That's not the point of the piece.
And I liked the dry sound of his drums, very much (but that doesn't mean all drums should always sound like that, or always be played like that, or that a different sound wouldn't work).