The Black Series, "Not a vehicle" and HasLab will lead the conversation in only a few directions.
Looking at HasLab history with comparable properties like Marvel and Transformers, it's usually something big and with near instant name recognition. With Marvel it was a giant Sentinel and the sweeteners were the added in figures. I didn't really follow the Transformers Unicron campaign. And with the two Star Wars campaign there were a number of campaign goals that were added which would augment the vehicles.
I have a few ideas so far:
CREATURE - The Rancor
Possible stretch goal figures - Luke (Rancor Pit), Gamorrean Guard, Oola, Malakili & Giran
PLAYSET - The Mos Eisley Cantina
This should probably include at least one figure to start - Wuher, the bartender seems like a natural start. If they went in this direction I would also hope for the as yet unreleased original Kenner cantina aliens as starters - Momaw Nadon (Hammerhead), Ponda Baba (Walrusman) and whichever Snivvian you would say is the vintage Snaggletooth.
Possible stretch goal figures - Dr Evazan, Cantina Band
PLAYSET - Imperial Throne Room (Return Of The Jedi)
Include a couple of Royal Guards
Possible stretch goals - Emporer's Wrath Luke, Imperial dignitaries