> you expect of AI the ability to use the vast knowledge on languages and platforms that already exist out there.

They do. Even completely novel esolangs have enough in common with other things that the current models don't even blink.

I really recommend trying it some time.

Not really - it doesn't seem to be much of a leap to be able to transfer that knowledge to new language. Honestly there's not a lot that's fundamentally new under the sun in new programming languages and solving a problem in a different language is just another problem for an llm to solve - obviously what's easy and hard for an llm is unrelated to what's easy and hard for a human so human intuition should be taken with a very large grain of salt, but my intuition is that it's not meaningfully different for the llm to figure out a new language vs figure out a weird 3rd party api to integrate with. For both of those cases you do need to give them access to docs and examples, it's not innate to the model, but even for languages it does know from its training data you still need to direct it on what style guide etc you want for your codebase to keep it consistent with your other code patterns.