Current yes, MMCCIII is included with the game. But as I said, MMCCII was not a product produced or created by Matrix Games, it was a community-created 'extra' that was thrown in as a freebie. There were a lot of these with Cross of Iron. As Mooxe pointed out, it was created with Java, a platform that's been discontinued, and we do not have the source code for it either, so we can't fix problems or update it to work on newer systems. All we can do is restart it and see how long it stays up, and that has (obviously) not been a practical solution for anyone.
If MMCCIII hosting is discontinued than I am hoping that we can make the multi-player server components available to players, so they can host their own campaigns.