[apta]

With Java getting value types, record types, and pattern matching it will end up giving all the other JVM languages a run for their money. Today, Kotlin is much more approachable than Scala, not to mention better tooling. Once Java catches up though, it will be a different story.

[vips7L]

Lots of good things coming for the jdk. I'm extremely looking for project loom (fibers) to land.

I expect kotlin to fall off everywhere except android once loom and the rest of project amber land.

[mbo]

When are higher-kinded types roadmapped for Java?

[apta]

I'm not aware that they are. It's a nice feature, but it might introduce unnecessary indirection is used inappropriately, that and the vast majority of languages get by without it without any significant hindrance.