No, not at all. Unless there is a large amount of training data relevant to the translation then LLMs are likely just to make up nonsense. Chisel is a very niche hardware description language.

Which might discourage an Open Source hardware project with shared ownership as large as a high performance implementation would require - as each cooperating company would end up using rather different products anyway.

I fear it'll become just an "Dump Over The Wall An Old Snapshot" of a few different companies work at best, rather than true cooperation.

There are lots of companies that have their own high-performance accelerator cores (though not general purpose). Multiple generations. Eg every FAANG (except Netflix, that I know of).

There are exactly zero such OSS cores.

So I think you have this exactly backwards.