It's curious that they changed that but also left the wording in the bottom disclaimer. Did the actual functionality of the game change, or are they just hoping that by stating it that way people will get the message?
Either way, it's still better to state it that way, even if it isn't as clear as it really should be. (I too prefer not allowing mix-and-match, or putting a clear in-game warning before proceeding.)
What I've heard so far from people who reported the problem is that they were pointed to the disclaimer and basically told sorry. But I don't know the results of further follow-up after that. At least the issue was noticeable enough (between the forums and Customer Service) that they did make some adjustments to the explanations.
