Disclaimer: I pretty much don't like Rust, but most criticism of it boils down to culture war.
Got curious and looked into it. All the architectures officially supported by Debian are also supported by Rustc.
- https://doc.rust-lang.org/beta/rustc/platform-support.html
- https://wiki.debian.org/SupportedArchitectures
I guess if you're a fan of GNU/Hurd it might cause issues?