Correct, however Hotspot isn't the only JIT compiler around in the Java world.

At least J9, Azul and now Graal, and then there is the plethora of embedded ones, but those ones wouldn't be able to use that much memory anyway.

It's not a JIT problem, it's a VM problem. Graal uses the same VM with a different (or additional JIT) JIT and inherits the same (intentional) 2 GB limitations.

While J9 can give you larger arrays AFAIK you're not guaranteed to get a single, contiguous memory region. You won't notice in Java but JNI criticals may return copies.

I haven't tested Zing, but Zulu is just HotSpot.