We could say that the existence of pre-agreed joint strategies invalidates standard decision theory.

It's easy to come up with scenarios where coordination is so valuable that you have to choose not to act on privileged information. For example, you're meeting a friend at a pizzeria, and you spot a better-looking pizzeria two blocks away, but you go to the worse one because you'd rather eat together than apart.

Psy-Kosh's problem may not seem like a coordination game, but possibilities for coordination can be subtle and counter-intuitive. See, for example, these two beautiful logic puzzles.