Today some of the masks will drop off - figuratively speaking. I don't expect an open battle between the GC favorites, but some of the guys in lesser shape will probably lose time, e.g. Adam Yates, Zakarin, D. Martin etc. Riders who crashed heavily yesterday could also lose time. It will become clearer who the favorites are. Jumbo will probably control the race.
In the attacking department Alaphilippe is certainly a candidate, but I'm also looking at Pogacar. He was the only GC rider in the first group yesterday and he seems eager to prove something in his first Tour. Maybe Daniel Martinez could try something as well. I hope the racing will be agressive, not just a sprint with forty.