Agreed that micro is a big advantage that AIs have held in previous AI vs. Human StarCraft contests, but the OP stated that the SC2 research environment will limit the AI to (elite) human APM levels, so that edge will be somewhat blunted. It's probably fair to question whether all actions are counted equally; I could believe that an AI could allocate their action budget more widely than a human can, even while hitting the same total APM.
More importantly, in my opinion, I'm not aware of any other AIs that have been competitive at the StarCraft problem using a Neural-Net-based implementation; from talking to PhDs in the field (but not from direct technical experience, so take this with a pinch of salt), my impression is that state-of-the-art RNNs just don't have the ability to encode the history of the game-world in a way that would enable them to be competitive. So it will require significant advances to the theoretical models to be able to compete using the sort of implementation that DeepMind will build.
More importantly, in my opinion, I'm not aware of any other AIs that have been competitive at the StarCraft problem using a Neural-Net-based implementation; from talking to PhDs in the field (but not from direct technical experience, so take this with a pinch of salt), my impression is that state-of-the-art RNNs just don't have the ability to encode the history of the game-world in a way that would enable them to be competitive. So it will require significant advances to the theoretical models to be able to compete using the sort of implementation that DeepMind will build.