So we shouldn't make those sections public because there might be some secret "brainstorming decks" there? Are you serious?

I'm not really sure what you are saying in that second part but the point of this is..
1. EntertainmentThis is the #1 reason why everyone is here. This is not about government secrets, it's about
fun. And seeing these secret areas is fun for people who have been following the War event. It gives them a rare glimpse of what's happening behind the scenes.
2. EducationWhen everyone gets access to these areas, they will see the mistakes the losers made, and the awesome strategic decisions winner made. This will help everyone prepare for the next War. It also helps newbies to understand the whole process.
These sections were made secret so that opponents cannot see what they are fighting against. They weren't made secret because they are some kind of top-secret Cold War agent meeting.