Some context about this here: https://arstechnica.com/information-technology/2023/08/openai-details-how-to-keep-chatgpt-from-gobbling-up-website-data/
the robots.txt would be updated with this entry
User-agent: GPTBot
Disallow: /
Obviously this is meaningless against non-openai scrapers or anyone who just doesn't give a shit.
I think this is a general question and problem for the whole fediverse, and can easily lead to the question of whether, or even when the fediverse is going to embrace having closed or private spaces or even invite only spaces, in order to try to secure some "human interaction only" social media.