Wow! I knew the Ke Jie vs AlphaGo would come one day, and probably the human team vs AlphaGo, but didn't expect the "Pair Go" (human + AlphaGo vs another human + AlphaGo). Interesting to see.
Centaur chess has been a thing since Deep Blue.
I think the problem their future of ai stuff is having is most orgs have no idea which of their zillion problems actually needs this tech. Hopefully this will raise more awareness.
In Centaur chess, the human gets to consult the AI. In Pair Go, there is only alternating play, with no other form of communication, leaving the human guessing at the AI's plans.
If I recall correctly, Nakamura used an older version of a weaker chess engine (Rybka). He also tried to force a relatively equal position (since he was behind in points anyway) which led him to lose because of risky play.
I wouldn't be surprised at all if Stockfish would lose to Stockfish + Nakamura or any of the leading chess players. These people have been using chess engines for analyses for quite a while now and certainly know their limitations.
The key idea of human+computer is that human does strategy and position evaluation, and computer calculates tactics and acts as a safety net to prevent human blunders. A weaker chess engine would still perform that function.
Granted it's all conjecture since no large competitions took place, but the mere fact that no such competitions took place suggests that the outcome probably won't be pleasant for humans.