We don't need LLM for that, and it would be very risky to trust not crashing a $250k machine tool with a $5k part in it that could kill the operator if something goes wrong
There is AI assistant for mastercam and other cam software, it promises to make 80% finished programs, but parts look really simple, like something you do on the first week of cnc training.
Mastercam already has Automatic Tool Pathing. It's essentially click "go." It'll spit out all the toolpaths to make the part. It'll be inefficient and if you don't tell it specifically what tools to use, it'll use 100 different tools, but it's actually not too bad if you set it up correctly. A number of other CAM packages have similar features now.