Put another way, would achieving strong types without type erasure only require a new language or also a new JVM?
Note: I'm not asking when or how erasure occurs. I'm asking what is demanding it. The inability to change the language or the inability to change the JVM. Or both.
UPDATE:
To be very clear, I am not asking about any implementation details. This question is about legacy. Unless I'm mistaken type erasure has been justified as something we have to live with for the sake of backwards compatibility. How it is currently implemented and when it takes effect are not at issue.
Any answer to this question should make clear if a new specification to a new strongly typed language could do away with type erasure and still run on the JVM as it is currently specified.