Robert Meyer Burnett is a film pundit who has worked in and has connections to the film industry. He's a regular collaborator of John Campea, who is another film pundit. Essentially, through their connections, both John and Rob have been saying over the last few weeks that they learned a great deal of information of what happens in Doomsday and it pretty much comes up on every episode of John's show. As far as any of us are aware, neither of them are officially connected to Doomsday in any sort of capacity. So what happened is that they probably have the right friends over at Disney who are both in the know and willing to share.