If this is correct, then I am vindicated in what I've been saying about this game right from the very first moment it was revealed. My claim has always been that they made this game for multiplayer first, and single-player is something they have grudgingly included in the game (because WotC compelled them to include it). As such, all major game design decisions have been made with multiplayer in mind first and foremost, with no regard for any negative consequences to the SP experience.
And this is a decision I will never understand, based on the likely percentages of people playing single player over co-op.