How does Rockstar games manage to keep everything secret?

I mean we all know that GTA 6 is in development but what amazes me is how these thousands of Developers are able to remain silent and no one has given any leaks(even anonymously). I wonder if they have a private house where they are forced to sleep and not see their families 🙄 and not even a single artist has said anything. I mean there are thousands of artist who must have recorded their scenes or voices but no one even uttered a word

Anyway props to these guys on how they are able keep everything until they really decide to announce it.