The colleague left 4-5 years ago for an external job. Part of the problem was the utility needed some enhancements/extensions and nobody wanted to continue it in Clojure. I think it was rewritten as an overhaul/revamp of the larger project it was part of.
I also left but for a different internal position where I can write C/C++, Java, Rust, Python (no C# in new group because new job is writing software to run on linux, and our IT does not support dotnet core - in addition there is no demand from us because we have a zillion lines of code all written before any dotnet on linux existed). EDIT: Old group can use C# because that work was on Windows (just to clarify C# wasn't dropped company wide).
Anyway, some orgs might be more receptive to "exotic" languages but I know where I work you'd have to fight really hard to do it. I was pleasantly surprised to see Rust got the thumbs up.