> ... the trailing lambdas feature. That is definitely directly OCaml inspired...

Kotlin has a very similar syntax to Groovy, which already had that feature (it looks identical in Groovy and Kotlin)... and I believe Groovy itself took that from Ruby, I believe (Groovy tried to add most convenient features from Python and Ruby). Perhaps that is what came from OCaml?? No idea, but I'd say the chance Kotlin copied Groovy is much higher as JB was using Java and Groovy before Kotlin existed.