Experts are always Experts of legacy systems
Elon has repeatedly confounded industry "experts" and people embedded in legacy systems. I'm sure he has no idea how to design and build cars or rockets. What he does do is listen to disruptive engineers, who typically come from outside the industry and then give them the authority to tear-up the "rulebook"
I wait with baited breath for the DoJo AI chip, which apparently is the first chip NOT based on von Neuman architecture.
(And I can't conceive how twitter would work without Remote Procedure Calls, my guess is one is talking about a narrow definition and the other a broad one.)
And yes, as the legacy engineer, I'd be worried about Elon throwing out all your code. You'd be better advised to offer a new architecture to Elon.