> how are they supposed to proceed with updating the Rust bindings if they don't want to write Rust?

If I've interpreted it correctly (and probably not, given the arguments), Linus won't accept merge requests if they break the Rust code, so the maintainer would need to reach out to the Rust for Linux (or someone else) to fix it if they didn't want to themselves.

And some lead maintainers don't want to have to do that, so said no Rust in their subsystem.