Only if they rewrite the world in Jawa and stop advertising compatibility with the Java eco-system, then they can use Jawa, Dart, Kotlin/Native, whatever they fell like.

I don't really get your argument. gcc has lots of non-standard extensions. Should gcc not be able to call itself a c++ compiler?

Android Java is a subset of cherry picked features of Java and its standard library, with support varying across Android version.

GCC is an ISO C++ and ISO C compliant compiler, plus a set of language extensions.

Any ISO C++ or ISO C code will compile under GCC.

Not every piece of standard compliant Java code will compile under Android Java.

Not only this produces a burden writting portable Java libraries, it creates a false perception to many developers that learned Java via Android and assume Android Java == Java.

The later point is usually used by Google when they sell how Kotlin fares against Java, because naturally if they would compare it against a proper up to date version, some of the plus points wouldn't uphold.