"I assume you’re talking about the original Mega Man. There was a Mega Man slot for this game – we had room for a character from that series. But when it came to the propriety of that character being in a fighting game, Mega Man has some problems.
If we were to adapt the original Mega Man character into a fighting game he would have to have a lot more extra moves and abilities, and that would then create a different Mega Man entirely. You couldn’t retain his original character as he is. So we looked into other Mega Mans, and decided that Zero had the best list of moves already in existence when it comes to fitting into a fighting game."-------
I dunno about that... I mean, Mega Man seemed to work for the past two MvCs, right? And, hey, as The Mega Man Network noted, some bright chaps managed to whip this up. It's not like it's 100% impossible.
There's always a chance for DLC, but Niitsuma's comment makes me feel like even that's a no-go. Guess we'll have to settle for Tron and Zero, for now.
Thanks to everyone who sent this tip in. Apologies for not getting on this sooner!