I know most of the fans didn't like 'The twins', Bay hated them too. Bay told that their will be a lot of dead in the last movie. Skids and Mudflap will be killed pretty early in the film I guess. I haven’t seen any photo from the two in Chicago. Just one photo butt it wasn't with the other autobots. Pretty logic actually, with the wreckers, wheeljack and the Ferrari 5 new autobots appear. I am pretty sad Jolt isn't their anymore I liked them though.