I guess it would depend on the rules of the sport. In soccer/football, the game can't continue without the refs, but just because there are no refs doesn't mean the game is over. Sometimes they'll leave the field in protest of player or coach behavior. There's nothing a ref can do if a player refuses a penalty that was assigned to them, so they'll typically leave the field until the player accepts that he's been penalized.
So in this situation, the board leaving would be a strong indicator that they're protesting the actions of the company or of the CEO. There's nothing saying they can't come back if the situation changes, or the company can forfeit the game and then it's all over.