That was approximately the answer Sam was expecting. She still felt that this was something that had been discussed, and she had a sense of foreboding about the wall, and what would happen to her if it came down. Obviously in Castiel's world it hadn't turned out well-- it had been something even an angel couldn't truly heal, only shift. But then, she supposed that an injury to her soul was different from an injury to any other, more tangible, part of her body.
"Guess we'll just have to see, then," she said. "Bigger problems now, anyway. Ought to keep my mind off it." She stabbed another bite of her salad, but paused before putting it in her mouth. "At any rate, I'm glad you're here. I think we're going to need everyone we can get to figure this one out."
She simply assumed that, despite being human, he would be involved in solving the problem of the realities collapsing. Obviously he might not be as powerful or effective as he'd been before, but he was still someone that cared enough about the world (or worlds, in this case) and the populations of them and didn't want to see them disappear. It was safe enough to assume that was true between worlds, right?