Impressive, but there's a couple of things I'd like to see them try one day.
Plug AlphaStar into a robot that physically interacts with a keyboard and mouse to control the game. This "robot" should only have what's relevant for playing the game and emulates a human i.e. a camera that looks at a screen (this is the only knowledge it has of the game), and two arms & hands with five digits that control the mouse and keyboard. Then limit its APM to the best a human can realistically do.
The other thing I want to see them address is the virtual training time. 200 years of StarCraft is insane. LiquidMana has been playing for ~20 years and of course he hasn't played the game 24/7. Lets pretend he has played StarCraft like it's a full-time job since he was 5; 8 hours a day, 5 days a week, for 20 years. That's ~42,000 hours of playing StarCraft.
Develop an A.I. that is only trained for that many hours of virtual game time.
If they can create an A.I. with those requirements, that can defeat top-level players, I will be completely blown away.