I can't but help think that he would have spent longer on it if that's what he really thought.
I don't think he believes in Rails any more.
It's clear that he was more excited about thing that are not ruby or rails and now considers rust better suited to the output of AI.
To be honest, I could see rust taking over from typescript/javascript as an output language for the web too. If no one needs to read source code any more why not use rust for everything?
I love Elixir/Erlang but we all know the "better stack" these new devs will choose instead for a web app is a maze of React, supabase, and Auth0.