Ughgh...I didn't even think of that! And knowing Balaji Telefilms, I wouldn't be surprised if there's a different bride at the mandap (Anika instead of Bulbul!).
I think the assignment is to do with Rohan's missing body...(depending on what Anushka did with the apparently dead Rohan) Vihaan and his team will probably find an interesting story in this matter... I just hope that Bulbul remains to be Vihaan's bride and Vihaan remains to be Bulbul's groom. That's it!