A larger problem for a potential adaptation would be trying to get Downey's Iron Man into a place where he can believably stand up and support a Registration act so passionately that he's willing to fight his former allies over it. So far, mcu Iron Man has been extremely distrustful of shield and the government both, and he's been continuously proven right about that, so something big would have to happen, probably several times over, to get him to that kind of about face.
That's what I thought too. This is a man who stopped manufacturing arms, refused to hand over his technology to the US government and military and was rude to a senator. Pretty much the opposite of the Stark of Civil War, from what I know of it.