I assume Google will try to replace Java with Dart, because they have recently been focused on Flutter [1] [2] and Fuschia [2] development which are (mostly) C++ and DartLang stack.
> I assume Google will try to replace Java with Dart
I would have expected this, but not after pushing Kotlin. Kotlin is shiny enough to temporarily distract the typical developer from the daily struggles with the abysmal Android API.
Kotlin and Java it will be for the next 10 years, for better or worse.
Dart is not very popular within Google itself, and Fuchsia is nothing more than a paid hobby project[0].
According to what Fuchsia developer Travis Geiselbrecht said in the public Fuchsia IRC channel,the OS “isn’t a toy thing, it’s not a 20% project, it’s not a dumping ground of a dead thing that we don’t care about anymore.”[0]
Given the level of activity on [Fuchsia's project repos][0], I find it very unlikely that it's just a hobby project. That amount of activity is on-par with Android itself. If it is just a hobby, it's an extremely expensive one.
[1]: https://flutter.io/
[2]: https://github.com/flutter/
[3]: https://github.com/fuchsia-mirror