I would be really surprised if they’d come out with a Kotlin native compiler that doesn’t also compile Java. That would just split the ecosystem for no reason, especially as Java is basically a subset of Kotlin in semantics. I wouldn’t be surprised if it will just take class files as input. Andrey already said they were going to implement a GC.
My interpretation of what Jetbrains people have said about Kotlin Native is that they think IoT/embedded is going to grow a lot in the future, which is probably true. These devices are getting plentiful and powerful enough that bare metal languages (C/C++/D/Rust) aren’t a necessity anymore and higher level languages make sense, but not powerful enough to run a full JVM. There aren’t many well known languages in this space of high level + native compiled. What I can think of there’d be Go, Java with existing AOT compilers, or native compiled .Net, and Go is still a much smaller ecosystem than the other two. I think Jetbrains thinks they can create a good enough alternative with Kotlin Native to have an impact. I’m not very familiar with the state of existing Java AOT compilers, but I wouldn’t be too surprised if Jetbrains thinks that existing tools are not good enough and it will be easier to create a new compiler based on LLVM. And a Java-ecosystem based language would be uniquely suited for that since it is the only major ecosystem that is mostly self contained, in the sense that it is very rare for Java apps and libraries to have mandatory dependencies on native libraries. Which is unlike the .Net, Go, and any other open source language ecosystem.
A Kotlin Native offering would offer the same selling points as Kotlin/JVM but for the IoT and embedded market. I.e. a language that is very easy to learn for lots of developers and a familiar environment with a huge library ecosystem. Splitting the Kotlin ecosystem by not compiling Java libs would be a bit nonsensical, since then you would just have a new language and a new ecosystem with few libraries, which is not a very attractive proposition to a prospecting IoT developer.
The only thing I’m missing is how exactly Jetbrains plans to profit from this. Selling more tools to IoT devs is nice, but maybe they’re also planning to be an IoT or Kotlin consulting company or something like that.