According to Niitsuma, the disastrous events that occurred in Japan not long after the release of MvC3 "threw off our whole development schedule." Eventually, a decision was made to release that content on a disc, along with tweaks to the gameplay, a new spectator mode, and other new playable content. Niitsuma characterized the content as "about half and half" between the originally planned DLC and newly developed content for UMvC3.
Speaking to the subsequent leak of the entire roster for the upcoming Marvel vs Capcom title, Niitsuma reluctantly accepted the situation. "It's a shame it got out, but that list, those names -- those are the characters we are adding to the game. But this is only a list of characters," he noted. "I think for the fans of our fighting games, that's where the real fun is -- seeing those characters move and act." As for when we'll see that? "Closer to the release date," he said. Unless it leaks out earlier, of course.