It hasn't. But the attitude towards using Rust for device driver development has now gotten very positive, especially post the recent kernel summit.

An LWN article about Rust in Linux that's very relevant to this discussion: https://lwn.net/Articles/829858/

Google has decided to go forward anyway.

Just like Android Linux compiles just fine with clang for the last five years or so, it now makes use of Rust.

https://source.android.com/setup/build/rust/building-rust-mo...

If upstream ever cares to support clang or Rust, that is another matter.

Unless I'm missing something, that link refers to building Android user-mode components in Rust, not kernel components in Rust.

That's correct, but it came after them rebuilding the bluetooth stack https://news.ycombinator.com/item?id=26647981