Dartz would be nice but I see them putting in Duke and Rafael before Dartz gets in, mainly because both of them have a good number of cards printed IRL that they could use for duel rewards (DDM monsters and Guardians respectively) also I could see them bringing in Zeigfried and Leon von Schroeder before Dartz as they also have a decent pool of IRL cards.
Oh boi Kaiba technically owned dartz in and the pink rose hair guy in the series. Since they are adding non manga characters such as Sartorius, Hassleberry and Chumley I don't really see any reason not to give us Dartz since plenty of people remember him.