Exactly. While there are a few academics who work in private for years and then surprise the world with an amazing breakthrough, most of modern science and mathematics is a collaborate process. Researchers make gradual progress on hard problems, and discuss issues with colleagues and students along the way. Some of those collaborators will then pass on the information to social media or public discussion forums or free-tier LLM prompts or whatever and it gets incorporated into the next round of training runs.

Two people can keep a secret if one of them is dead.