> given there is no training dataset, any other language would work better with AI.

I guess it depends on what "would work better" really means, but I don't think it's always a given. I've made my own languages, there is no available training set on exactly those, but AI with a prompt can figure out how to effectively use them as much as any other language, it seems to me. I guess it helps that most languages are more similar to each other than different, but even experimenting with new syntax seems to work out OK for me.