I think it would be better to approach it from the other side, the priority is not to design a language for LLMs but a language more suitable for humans to think with. And not a natural language like English, which is inconsistent and allows illogical formulations, but something like Esperanto or Interlingua (Latino sine flexione). Something that is based on mathematics and logic at the bottom, like Lean, with enough abstraction layers for a person to be able to "speak" with the machine intuitively.