They re going to have to do more than this. They can surely make an AI that determines which % of the LLM answer is owed to which website / source. Then either pay them ad revenue or demand the user to pay to see the rest of the answer. I don't often click on AI answers, and i assume most people don't. I find myself clicking beyond it only when the answer is bad.
If google doesn't do that, publishers will respond in a vicious way, like purposely poisoning content to mislead their LLMs.