Hopefully Stussy finds a way to meet Ms. Bakkin. An explanation on what the deal was between Ms. Bakkin and Vegapunk would be great IMO. Plus find out the mystery of Weevil. Is he a defective clone of Whitebeard? A test tube baby using Whitebeard's and Ms. Bakkin's DNA? Something else?
Without Vegapunk (Stella), Stussy needs a new purpose. She can not go back to the World Government with Lucci and Kaku knowing of her betrayal unless they keep her secret. She could possibly go back to the Underworld. Or help Morgans.
If she were to travel to Elbaf, which ship would she get on? It's looking like the Strawhats will be separated once again so she may hitch a ride on the Sunny or a Giant ship.