Actually, CIG promissed that not just the forums, but the entire content that they share would be exclusive for backers. They even used that as a sales bait, making people rush to pledge at the beginning and during the first months after the end of the original funding campaign. There is no doubt about that, since its all public record. Ask me and I bring the proof if there is interest on that.
Technically they decided only now, 10 months behind the schedule, to accomplish in a very tiny part, with that promisse.
CIG is a case study in how not to keep your promise and get away with it.