I have a theory, that involves the Theory that Lola is in fact Big Moms daughter. If Sanji and Co. have actually been captured by the Big Mom pirates, and are brought before Big Mom, then I believe that the Vivre Card that Lola gave to Nami is going to react, and Nami is going to mention the events of Thriller Bark to Big Mom, and tell her that Lola said that her Mom was a Big Shot pirate in the New World, and that if the crew was ever in a bind, to look up her mother, and she would help them...
Big Mom will descend upon Dressrosa to help the Straw Hats