I just returne3d from seeing Disney Dream with a load of passengers. I vcan tell you I never saw the teens oboard, which tells me they were having a ball in their priovate areas.
On dream the teen 15-17 area is VERY isolated, almost impossible to find. You have to walk through a an area that looks like a crew area, or use the stairs from below.
I can't say the Edge (12-14) has the same kind of attraction, though. I t was empty a few times when I went in there.
Disney is not fanatic about age separataion, they may have let some of the tweens into the teen area.