This is not exactly novel. In the 2000s, someone made a fully functioning Perl 6 runtime in a very short amount of time (a month, IIRC) using Haskell. The various Lisps/Schemes have always given you the ability to implement specialized languages even more quickly and ergonomically than Haskell (IMHO).

This latest fever for LLMs simply confirms that people would rather do _anything_ other than program in a (not necessarily purely) functional language that has meta-programming facilities. I personally blame functional fixedness (psychological concept). In my experience, when someone learns to program in a particular paradigm or language, they are rarely able or willing to migrate to a different one (I know many people who refused to code in anything that did not look and feel like Java, until forced to by their growling bellies). The AI/LLM companies are basically (and perhaps unintentionally) treating that mental inertia as a business opportunity (which, in one way or another, it was for many decades and still is -- and will probably continue to be well into a post-AGI future).