It doesn't matter it's like this since 1968, they should change it or at least go to 4 years cycle like EURO, it's crazy to have that tournament each 2 years. Back then they did not have players in Europe and ACON is not doing any favours to African players, I'm fairly sure many teams avoid signing them unless they're worldies (for big clubs) or great quality for the money for smaller ones. It's specially wrong for Premier League as it does have a busy period around ACON and losing your players in such times is very wrong.