Are you implying that them attempting a Rust rewrite would fail, and this is why they’re not doing it?
If that was the case, it just makes no sense at all to use JS. Take the free performance gain and don't read the code.
Here is the prompt they can use:
Claude, migrate Claude Code into Rust. Make no mistakes!
Well, Anthropic spent many $ teling everyone that code is dead so this doesn't matter to them does it? Their business logic can be written in English!
codex VSS - 600Mb