No they could not. Rusts standard library heavily uses dynamic memory allocation and panics, for example. MISRA C:2025 Addendum 6 covers MISRA rules that still apply to Rust, as an example of how one would restrict Rust in safety-critical contexts.
Panics can still exist, of course, but depending on the system design you probably don't want them either, which is a bit more difficult to remove but not the end of the world.
I hadn't seen that addendum though yet, that's very cool!