How will they enforce this? There's no easy test if an LLM write a given post. Perhaps they can post honeypot questions.
1. It's relatively easy to detect "default ChatGPT" output with very few false positives, and I've written a crude version of one myself.
2. It's doable to make LLMs generate output that are impossible to write such a detector for.
I've made a service[1] that does the second part, rewriting content to fit in with a certain community, one of which is StackOverflow.