Another factor that we should think about ...
On Monday, we want the story to be about the seeding for the women's team, and their chances of making a deep run. You don't want to take that headline away by announcing a coaching change then. You want to have the coaching change already announced.
Also, I believe the NIT/Crown invites will come out on Monday? If so, I would think you would want to be able to make a decision about whether or not you can accept that invite without the uncertainty of the coaching decision still hanging over your head.
There's no reason to keep players, assistant coaches, and Fran himself on pins and needles all weekend. If you've made a decision, make it public.