"The term "Proof of Work" or POW was first coined and formalized in a 1999 paper by Markus Jakobsson and Ari Juels."
https://en.wikipedia.org/wiki/Proof-of-work_system
His present agenda is a separate issue (I don't know what it is), but he is no amateur observer when it comes to BTC.
But as you said in another prior post here, he could have an agenda that clouds his "recommendation". Even if he knows crypto backwards and forwards, being an authority on a subject doesn't mean you have some unique gift to predict future evolution of the Bitcoin ecosystem. We have plenty of "experts" that have declared Bitcoin "dead" a few times, too. I'm not exactly holding my breath for what this guy has to say.
I'm wary of self-appointed experts in general, especially this late in the game. Where were they when the whole enterprise was just getting started? Too deep into their own pet projects to contribute? The timing seems a bit suspicious to me.