It just might. But, what about the band? It will really stink if they sing the same crap they already sang.
Certainly they should not sing something they've already sung. Give them a day or two to prepare. However, how does this work if they pick a couple on the same night they hold the sudden death? Will they go stand-alone "no band" like they did in the final judging to get to the final 36?
This will be interesting, none the less, to see what happens.