TakaraTomy’s official twitter account has shared in-hand images of Studio Series 86 Coronation Starscream, giving us a clear look at what changes have been made from Earthrise Starscream, at least in robot mode.
In these images we can see the new hinged fingers and we can see the vertical stabilizers are solid blue for greater animation accuracy. The jet mode and throne are not pictured.
To dispel a rumor, no other changes were ever promised. The sample first shown at Fan First Friday was a test shot. The strange colors were just what the factory had at the time, not a indication of new tooling.