Training on X doesn't run afoul of fair-use because it doesn't redistribute nor does using it simply publish a recitation (as Suchir suggested). Summoning an LLM is closer to the act of editing in a text editor than it is to republishing. His hang up was on how often the original works were being substituted for chatGPT, but like AI sports articles, overlap is to be expected for everything now. Even without web scraping in training it would be impossible to block every user intention to remake an article out of the magic "editor" - that's with no-use of the data not even fair-use.