Kyle Shanahan is an offensive minded coach, having Matt Ryan allowed him to perform at a top level as an offensive coordinator (SB jokes aside), he doesn't strike me as a guy who would focus on the defensive side and roll the dice with a game manager QB, a guy like this need a QB to implement his philosophy and then build around.
There is no stability without a QB, I see the 49ers as a top contender for JimmyG services now that they are cleaning house.