I understand what they're trying to say but this statement is factually incorrect. Answers never used to have ads, and now they do.
In the very first example, if ChatGPT wasn't running ads Heirloom Groceries wouldn't show up, therefore it is a different answer.
OpenAI is splitting hairs and implying that the ad and the 'answer' are two separate components making up a response, but that is not how users will see things, and OpenAI will have ever increasing incentives to blur the two.