It's a nice historical overview of using search and ML for formal games like chess.
But - this is not the game developer usage of "game AI". Where are wargames, where are artificial characters, where is interactive storytelling, where are realtime control systems, and so on, and so forth? The doc is missing a lot of the actual history of game AI, which is much wider and more varied than presented here (and ML approaches are still in minority).
Anyone interested in game AI history should definitely check out the past proceedings of the AIIDE conference: http://www.aiide.org