There are at least some studios using Rust. Chucklefish did for a while though they ended up stopping. Ready at Dawn was using Rust at one point but not sure if

There are at least some studios using Rust. Chucklefish did for a while though they ended up stopping. Ready at Dawn was using Rust at one point but not sure if they still are. Embark still is so far as I can tell. It certainly isn't a language for every gamedev shop but some seem to be taking it seriously.