I was pondering similar thoughts. Will LLM assistants ossify our current programming languages? My limited testing seems to show LLM assistants do well the more popular the language is (more data in its training), so is the hurdle for adoption of something new going to get even higher? In an alternate universe, if LLM only had object oriented code to train on, would anyone push programming forward in other styles?
Yes.
But today the only two reasons to use niche languages are[0] 1) you have existing codebases or libraries in that language 2) you're facing quite domain-specific problems where the domain experts all use that language.
In either cases you won't just use Java because LLMs are good at Java.
[0]: besides for fun or 'for resume'