Ed Boon made a tweet to Rocksteady saying that he can’t wait for them to finally reveal it.
Context tells us that he knows what it is and has possibly seen it.
This is the most credible tease we’ve gotten and it’s even more credible because it’s not a leak.
It could very well be Outlaws as the leak suggest but don’t allow yourself to think it is just yet. It could be something far different.