There's a lot of enterprise data science being done with Java/Scala and the Hadoop/Spark ecosystem.

MXNet also makes deep learning a first-class citizen in Java, but yes the research community is firmly entrenched in Python atm.

I see JDK languages as being in a decent spot for deploying ML/DL, and maybe an "emerging" language for training DL models.

Folks like Jeremy Howard have increasingly been expressing growing pains with Python and TensorFlow has been looking for something with a better type system like Swift.

If I had to take a guess, I'd say that Python is likely going to be sharing the ecosystem with a language with a better type system and performance like Julia or something on the JDK.