That's true Google never named Kotlin as a replacement to Java. Although naming it a first-class Android language seems like a pretty big move (actions over words), and given an official option between Java and Kotlin I believe most dev's will begin moving towards Kotlin. intended was probably the wrong word for me to use, should have been probable or likely.
It may be true for Swift but Google never claimed Kotlin is replacement of Java. I guess people are getting overly excited and making claims that Google did not. Kotlin is low effort developer friendly move by Google. Jetbrains will do work on language and tooling and Google would provide some Android-Kotlin related docs and support.