Not necessarily, not all tactics can be used symmetrically like that. Many of the sites they scrape feel the need to support search engine crawlers and RSS crawlers, but OpenAI feels no such need to grant automated anonymous access to ChatGPT users.

And at the end of the daty, they can always look at the responses coming in and make decisions like “95% of users said these responses were wrong, 5% said these responses were right, let’s go with the 95%”. As long as the vast majority of their data is good (and it will be) they have a lot of statistical tools they can use to weed out the poison.