I thought they were going to hold this until Clojure/conj 2024. No particular reason to believe so (besides Clojure 1.10 being released around the same time as Clojure/conj 2021 and the Datomic-becoming-free announcement being done at the very start of Clojure/conj 2023).

Still waiting on spec2, though... for now I am working around rigidity of specs by using Malli but it really isn't a first-class citizen in Clojure (mostly due to inability to check macros, and this is by design of the Clojure compiler). But you can emulate the ideas of schema/select by manipulating malli schemas as data.

The changes for functional interfaces also means we no longer have to maintain utility macros like

  (defmacro ->Consumer [f]
    `(reify java.util.function.Consumer
       (accept [this arg#]
         (~f arg#))))

and instead just pass functions directly.