I'm guessing he is the guy from the knife grinders australia youtube channel.
That is an interesting thought, the thickness of the oxide layer forming in stainless effectively thickening an apex to make it not appear to have as fine of an edge radius.
I wouldn't really personally stand by any of that stuff 100% until some electron microscopy could verify what is actually happening there.
Otherwise its just guessing. And sometimes things that happen on that small of a scale don't do what we might expect.