Don't get me wrong, it's an interesting idea which deserves pursuing, if nothing else but to satisfy our curiosity and seeing to what if anything it's applicable and suited. (and even if the answer turns out to be "nothing", we've still learned something!)

But going from there to making strong claims about it being a more or less universally superior paradigm for computing and writing code, with little to zero evidence, that's a huge, huge stretch.

To the degree Erlang and Actors work, I think that's kind of a happy coincidence, and not due to any rigorous work on Alan Kay's part.