Indeed. Rust is the language that the smart kids are using to think about higher-order programming concepts. It has begun to supplant Lisp and Haskell in that regard.
My reference point is Rust because I've worked on or in Rust for most of the past decade, but I think the relevance of Rust for programming language design more broadly is that it is the most well-typed widely deployed imperative programming language. In this way it has an advantage over Lisp or Haskell if you're trying to think about how we might statically analyze imperative programs, which is what I'm personally most interested in.