Due to a lot of rock falls on the Grand Couloir (3 rescues yesterday, monday, 1 this night) the ascent of Mont Blanc by the normal route is not recommended at the moment. Better to postpone your ascent. The Three Monts Route is in bad shape this summer and very technical : not recommended more than Gouter’s route.
In the last days, we heard about always more rockfalls in few areas of the massif. Be careful and prefer rock climbing (aiguilles Rouges, compact granite) than snow or mixed routes.