Is this Vivi/Morgans storyline even going anywhere?
Vivi's plotline is based around two elements:
1. Falsely framing governments in order to control them
2. Revolution against corrupt government.
Currently Oda is connecting Vivi to two groups: Morgans newspaper business, and the Revolutionary Army.
So, I imagine we'll get something along these lines:
Morgans becomes wanted for his Gear 5 poster, beating up a Cipher Pol Agent, and "kidnapping" Vivi and Wapol from the Reverie.
Now a wanted criminal, Morgans becomes the propaganda/newshead of the Revolutionary Army, working under Vivi to spread the truth. It's possibly he uses Vegapunks knew Radio tech to do this.
And Vivi joins the Revs as the "Red Line" officer, as she's been to Mary Geoise as royalty of Alabasta. But still joins the Straw Hats, IMO. Still really hoping Vivi gets Kuma's Fruit, too, but that would take a lot of plot occurrences at this point.