Yeah, if Nutaku'll stick to DMM schedule (and they said already they will) bride versions of winners should be added with limited gatcha (with increased drop chances probably) in event 16 (currently is event 7).
I don't see how it's related. You can vote for any girl in the contest even if you don't have her.
I wonder what happen if Orchid place 2nd or 3rd... Would her bride version be 6* like in DMM version of the game or would Nutaku just make her 5* with DMM arts...