Ok, then let's go with that viewpoint and apply it to the original question: How much do you need to remove from the training data such that from what remains,

Ok, then let's go with that viewpoint and apply it to the original question: How much do you need to remove from the training data such that from what remains, nothing harmful can be "merely interpolated" (which you acknowledge the LLM is in principle able to do) and anything harmful would require something "new" that is not in the training data and that the LLM is incapable of coming up with. The argument is that there won't be much left in the training data if that's your approach.