An issue I see here is the relatively rapid trend changes within e-sports compared to more traditional sports. What happens when League of Legends 2 is released

An issue I see here is the relatively rapid trend changes within e-sports compared to more traditional sports. What happens when League of Legends 2 is released (or everyone drops it and moves to DOTA 2)? Or Starcraft 3? Would it not be more appropriate to classify e-sports as a single sport, with various subcategories for the individual games (or even game types)?