IMHO, ML people are pretty pragmatic, possible due to the fact ML itself a mixed paradigm with people from different background, so they don't hold religious belief towards programming languages comparing to some pure CS background folks.
Rust is entirely practical and well suited for the task. And yes, people use rust.
What I am objecting here, are those annoying cool kids try to sell their flashy green solutions, like 'A new machine learning library written in Rust' to other people, because 'yeah, Rust is better programming language than C++'.
That is what I called 'religion belief', for those people who don't really care what problems they solved, they just naively assume they are better because of the language they are using is different.
I don't think people are saying that their solutions are better just because they're in rust. Maybe somewhere someone is, but the majority of what I see doesn't really sound like that.