Coffee Script is a transpiled language and it has become irrelevant when lot of the language features it offered is now natively available in ES6 and up (it has definitely inspired lot of ES6 features like fat arrow functions).

Rust on the other hand is not a thin layer on top of something like Coffee script. So it does not need to keep up with 'something' for decades. As long as it continues to do its current job of making systems programming safer and fun, it is going to be here for a long long time.