One of the lead authors, Daniel Kokotajlo, worked at OpenAI for years before quitting. In 2021 he wrote a remarkably accurate forecast of how LLMs would develop over the following 5 years[0].
I think it should be obvious that he understands that LLMs are trained via next-token prediction.
[0]: https://www.lesswrong.com/posts/6Xgy6CAf2jqHhynHL/what-2026-...