Uh, guys. The franchise is actually the sole property of Kouichi Yotsui since the beginning, not Capcom.
The reason why the sequels and cameos were possible were because of temporary license obtaining.
There is a chance that even if Capcom wanted so much for Strider Hiryu to be in MVC3 that Yotsui could utterly refuse the possibility.

And since he's bound to Square-Enix to make Necromachina, shit could go all sorts of wrong if we saw Strider in a game outside of NM's production, even if he's not in the game.
S-E pulled that contract binding shit off before on other staff-types, be they directors, producers or composers.

Then there's the case of MVC2 on PSN and XBLA, where one could argue "But that would mean they'd pull him off of the roster!"
First, it's a port of a port of a relatively old game. As if they'd remove essential content from the port of a port anyways.
Second, this is a whole new game we're talking about here. Strider Hiryu's last fighter appearance was CFAS, and look how that turned out. As for NxC, both Capcom AND Namco had to get the rights to the franchise.