I don't know if this is what you would say falls under the category of "vision casting" or not but I do think there is going to be a slightly bigger gap between the Leafs GM(If they hire one, Shanahan wouldn't even say for sure at the Babcock press conference) and your typical GM. I don't think the Leafs GM, for instance, will get to decide who to trade or what free agents to go after. If the team is looking to trade a player and gets multiple offers, I don't think they'll decide on which one to accept.
And resultingly, if that ultimate decision making power rests with Shanahan, then any attempts to make the GM the "public face" of management will probably backfire. Toronto media and fans aren't dumb. They, and we, will know if we're talking to the guy in charge or not. If he doesn't make the decision on trading Kessel for instance, but he's in front of the media explaining why they traded Kessel, nobody will be particularly happy.