To me this seems like an odd pairing. I'm not sure the Marvel universe fits with Telltale's style of games where everything is done on a smaller scale, and the choices seem personal and important. I can't really imagine the kind of choices you'd have to make with an Avengers character.
"Do you want to kill the 500 powerless aliens on your left, or the 500 ineffectual robots on your right?"
"If you press X, character A will die and won't come back to life for 10 minutes. But if you press Y, character B will die and we won't find out that his death was an elaborate trick for
15 minutes."

This is my smart-ass way of saying that Marvel (particularly in recent years) is all about scale, with almost no focus on consequences. Which is pretty much the opposite of what you'd want from a Telltale game.
Then again, as I'm typing this I realise that I just kinda presumed that it would relate to the Avengers somehow (because most things do nowadays). They could make a great Telltale game out of somebody like Daredevil.
Daredevil would actually be the perfect character to use, though I'm not sure whether the television show that just came out on Netflix would make them more or less likely to pursue this option. Probably more. He isn't too powerful for a game like this, he works within a small area, and his story is all about the complexities of morality and the consequences of being a vigilante. Seems perfect for this kinda game.
Then again, there is the problem of him being blind and how they address that in the game. But they could use some creative license to get around that. Or even if they thought it was an insurmountable problem, they should still pick somebody
like Daredevil. Someone a little less powerful and more grounded. They have enough of those character, they're just not the most well known or the most popular ones right now.