I think Contador might do something in this stage
According to gilbert the descent at the end is really technical so i think Contador is obliged to do something
. Maybe together with voeckler, valverde, purito orso.
I don't see any reason besides hiding your true form for not doing it but Contador is not that kinda guy. Besides if by some miracle he has the yellow jersey there's a TTT next stage thus he'll most likely lose it and giving Froome a mental hit that early would be a great thing. Obviously i'm assuming Froome won't be able to follow
The descent will be crucial.
And that's also a great thing about sky, it doesn't matter if they've the yellow jersey or not they'll always ride. They only have one game, they could play out Porte in a stage but i think they'll never ever do that. It's all about Froome.
Edit: I forgot Sagan of course. Contador needs to be with Sagan at the end of the climb and try and follow him in the descent.
Putting Froome on a constant pressure is advised imo. He might make a mistake, try and get him out of his comfort zone. He forgot to put on a jacket in T-A stage 6 for example. That stuff can make you lose the tour.