I just found this the other day while messing around in training mode. This differs from the suicide trick on Dreamland and Smashville. Basically, if you position your opponent perfectly at the edge and roll behind them, you can do a suicide throw. Not very practical in a real match, but could be used to punish a shield break. Here's a link that explains it in detail:
https://www.youtube.com/watch?v=LakY8wJDtEk
https://www.youtube.com/watch?v=LakY8wJDtEk