> real structs
I'm not even sure if value types are conducive towards immutable, persistent data structures. I'm certainly excited for project Valhalla but I'm not sure if Clojure, nor any Clojure-like JVM language, written in an idiomatic fashion, would really benefit from it.
> light-weight concurrency like Go
Project loom is already in preview mode. Lightweight concurrency is nearly here for any JVM language, and once it's fully released I will likely have zero reason to use core.async.
> type support
Static typing is A Thing you can choose to do, but I doubt you would get many daily Clojure users agreeing that it is "better". I think it's different and better in some circumstances but not necessarily others. It definitely feels trendy these days, sorta like how dynamic typing felt trendy 15 years ago.