That's an interesting interpretation. My interpretation is that they simply weren't able to do it yet (not for a lack of trying though), and so they gave up. It's not obvious at all to me that there is a way to simply scale their approach to the real game. I mean, certainly there is a way with infinite computing power, but it's not clear to me that even with all the computing power on earth currently this approach would work. 18 out of 117 heroes does reduce complexity quite a lot, especially when you pick ones with less complex mechanics.
>They weren't even trying to abuse the reaction time of the computer
They introduced a constant reaction time, but they still "abused" the interface they are provided. If this was a task in the real world, the AI would have the same interface as humans: The screen. They would have to move the screen and run object recognition algorithms on the rendered values, and they would have to "click" on units (not physically) instead of being able to internally select them. This would introduce completely different (and more realistic) reaction time parameters, because if a hero starts an animation it might not be immediately clear which animation it is in the first 5 frames, but the API will provide the value immediately.
AlphaStar's strength dropped considerably for example when they realized that the AI being able to perceive the entire map at once was an unfair advantage and restricted it so that it had to move the camera around. But still even AlphaStar is using an API instead of just the rendered output, which enables things like selecting units that are hidden behind other units, which for a human player is literally impossible without moving it out of the way first.
I think for AI to be able to claim that it is better at a game than humans, the AI ought to be playing the actual game, and use the same interface. (Not necessarily physically, you don't need a camera and a robot, but the AI's input should be the rendered output of the game, and the AI's output should be mouse movement / key strokes.)
You might think that would be a trivial and useless exercise (like it would be in Chess/Go), but I'm really not convinced of that for video games. There are a lot of examples where even playing a frame-by-frame recording of a fight you just can't tell what exactly is going on in a fight until a couple frames later, but the API will always provide floating-point accurate data of everything. This is a huge advantage that just doesn't translate into real world tasks when the AI has to use cameras and sensors to make sense of the world (in automated driving for example) just like we have to.