There is a big difference between everyone seeing the same splash screen announcing upcoming content and then posting about it, and discussing unreleased content that may or may not be in the beta stage.
We all had those Street Assault splash screens, and even had units placed in our inventories in preparation before the event launched. Gree seemed pretty keen on getting everyone all hyped for that.
Beta testers leaking unreleased content just confirms Gree has no business trusting any of them. We will all see new stuff when Gree wants us to see it. Until then, nobody misses what they don't know about.