Be careful guys, the guy who wrote the article haven't played the game, he is using Capcom Unity Brasil and WB Games Brasil as sources, the dude seems to be only inferring that there are going to be endings for arcade mode. The only thing that is mentioned that I haven't seen anywhere else is that beating arcade unlocks colors for the team used.
Oh, right, at the top. The writer says
"Following revelations in Capcom Unity Brazil and WB Games Brazil, where the nearly final version of the the highly criticised game was played, details about the modes shown in this entry of Marvel vs Capcom have presented themselves."Tras revelaciones en Capcom Unity Brasil y de WB Games Brasil, donde se jugo la versión casi final del tan criticado juego, se han presentado detalles de las modalidades que muestra esta entrega de Marvel vs Capcom.
Sounds like a second hand fluff piece.
I don't think there's endings, or if there are this article has no idea if they do.