So this is what you get when linting JVM Clojure (see screenshot). When I would remove the magic for goog.array/goog.object then the error message would become the same for CLJS.

You can disable this with {:linters {:unresolved-namespace {:exclude [goog.object]}}} already. So this would probably be sufficient, unless it's preferred to have a bespoke message around CLJS deprecating this.

I can make a new clj-kondo release with the goog.array / goog.object magic removed when CLJS will be released (on or around the same day).

Just making sure: should any namespace except goog or goog.base follow that rule from now on?

No specific preference

The rule doesn’t extend to ClojureScript in general - i.e. it is of course useful in the writing of macros

The rule is specifically for Google namespaces because they might become a module at any time

I don’t think we’ll ever drop old style definitions - we could be a bit more vocal on the Closure list that there’s just no value in these new ways - just annoyances