How is what he's arguing significantly different from video lectures? We've had VCRs with the ability to replace a classroom like this for a long time. But, other than teachers who would sometimes show a video during his class, videos haven't replaced teachers.
I had a class in college that was broadcast. It wasn't as engaging as in person, even though the lecturer was engaging. There was no opportunity for discussion, though some lectures don't have much opportunity for that, anyway. But, K-12 aren't 200 person lectures. They're much more interactive.