3. The Heritage
A lot of speculation has focused on precisely who Cumberbatch is actually playing, with suggestions early on claiming that John Harrison was no more than a misnomer intended for misdirection, and that he would be playing an older, more iconic villain in new dressings. This is not yet the place to get into specific details, but Harrison's success would have been more pronounced whether any revelation of identity was made or not. The marketing campaign that hinted and hinted without openly entertaining rumours, was genius in drawing unexpressed but unavoidable comparisons between Harrison and Gary Mitchell and Khan, because it established a heritage for the new villain that the narrative would never have had to play to anyway. Whether there is a revelation or not is not important, because canon has established a positive link for the villain in fans' minds, and though this could have been disastrous for a poor performance, that thankfully is not the case with Cumberbatch in charge of the role.