Tangential note: there is already a community effort[1] to rewrite GNU commandline tools into Rust and Canonical shipped the rust version of the /bin/utils in Ubuntu 26.04 Resolute Raccoon by default[2] in their "oxidizing" initiative.[3]
PS: Linus Torvalds has confirmed that the existing Linux kernel will never be fully rewritten in Rust.[4] Let's see how well that statement age.
As soon as Linus retires, there will be an initiative to rewrite the Linux kernel in Rust assisted by LLMs. Either that, or some company will fund a fork before that. Imagine, man pages full of emojis!
And between rustc_codegen_gcc, projects like https://github.com/FractalFir/crustc, the ongoing addition of backends to LLVM and Rust, and the eventual removal of obsolete targets as hardware goes away, that's less and less of a problem.
Since the Rust support in the kernel is not optional, it already has an impact on platform support, no? Or maybe they are using the gnu toolchain to avoid that?
Rust support in the kernel is still optional; it's currently only allowed in drivers, and drivers only use Rust if they can accept running only on current Rust targets (which is not a substantive limitation).
I expect Rust to eventually get used in the core kernel, or in drivers that everyone wants to use (e.g. some new bus or device on most new hardware), but I expect that by the time that happens the set of targets supported by the kernel and the set of targets supported by Rust (including through things like crustc and codegen_gcc) will have converged sufficiently.