AI Playcalling

In light of recent news (this, among much else), how long until someone tries to implement AI playcalling? Some obvious difficulties in identifying and loading the pre-snap positioning / motion of the opposing teams (particularly on offense) and getting the play call in on-time (particularly on defense). But if that can be overcome - and it seems like it could, even with current tech - this seems like a legitimate, perhaps even inevitable, option.

Thoughts on feasibility? Legality? Impact on the game?