I don't know Kotlin, but judging by their "Kotlin for Scala Developers" article I don't know if it would be a big enough jump to get people excited, especially since a project like this would take years to come to fruition. I think Scala is a good first try at what the successor language could be, but it has two problems: its reputation as a hard language, and the fact that it partly deserves said reputation. (Maybe if Odersky succeeds in simplifying the concepts underlying Scala as he's trying to now with Dotty, the result will be a potential Java-killer.) Oracle would have to fund a research project to choose an existing candidate and spend years developing it to fit the role it would play in the market. Which sounds very unlike Oracle, so I'm not holding my breath.
EDIT: And to your point, I think it's a bad sign if their most profitable customers think that none of the Java language updates they've released in the last ten years is worth upgrading for. The longer their customers stick with 2006-era Java, the longer they pass up Oracle's current offerings, the less attached they feel to the future of the platform, and the more likely they are to make a big change when they do make a change.
