Us - survive a Voldemort encounter? When Harry won't be there?
Seriously, while I think it'd be cool to see Voldemort, if Harry won't have a presence in the attraction (and apparently he won't), it wouldn't be nearly as exciting without the "hero" defeating the "villain". And I feel like, once again, Voldy would be represented on a musion screen effect basis.
However, I do have to say it sort of sucks that we've had no sight of the villain in either part of the WW. Maybe this will change that, but I'm not counting on it. I think it's a pro and a con, on the one hand the suggestion of Voldemort is scary and you don't know where he could appear. On the other, he's the scariest thing in the world and we never encounter him...