I think the difference here is that a human intentionally built a dataset containing that information, whereas Pi is an irrational number which is a consequence of our mathematics and number system and wasn't intentionally crafted to give you NYT articles.
Well that depends on what you're trying to prove. If you think it's a copyright violation to include the articles in the dataset _at all_ then it doesn't even matter if ChatGPT can produce NYT articles, it's a violation either way. If including the articles in the dataset is not in-and-of-itself a copyright violation then things get complicated when talking about what prompt is required to produce a copyright-violating result.
