Thought experiment. If we keep Woodson, how good would next season need to be in order for him to get a fifth year?
In my opinion, we'd have to be at least as good as last season. And even then, there would still be grumbling if we make an early tourney exit. If he misses the tourney again he's definitely gone. Even if we sneak in as a 8-10 seed or something, I think he's still likely gone.
So the question - how likely is it that we are at least as good as last season? If you're the AD and you think that is unlikely, what's the point in waiting a year? Just move on now.