I would be liked to give Capcom Fighting All Stars a shot. It had some really obscure characters and some others made specially for the game. Instead, we got Capcom Fighting Jam, basically a CAPCOM take on the MUGEN concept. And a shitty one i may add. Later most of those characters appeared in others Capcom fighting games.
Ingrid - First appearance later on Capcom Fighting Jam. She got a 3D Model as a place holder for Chun-li in Tatsunoko .vs Capcom
Batsu - Later as playable in Tatsunoko .vs Capcom
Alex - Playable in tatsunoko .vs Capcom
Ryota Niitsuma (TvC producer) also stated after MVC3 development that Akira, Hinata, Charlie Nash, Mike Haggar and Strider Hiryu were all considered for TvC as playable characters. The last two were selected for Marvel .vs Capcom 3 as playable later. The only missing one would be Poison, D.D and Rock. Capcom hasn't even stated those original ones even existed outside of Fighting All-stars :P