Doubt it'll happen. If I'm not mistaken, the latest update (1.08, I believe) is the last one that added additional content to the Arcade since it was for the final DLC.
But if we do get more Ubi game assets, I would certainly like to see more large city buildings and other unique props. The Division would be great for that. Maybe we can even get props that were used in the subway parts of that game. Wildlands and maybe even Rainbow Six Siege and The Crew would be good additions as well.
Since it has been confirmed that we will not get respawning vehicles or new game modes, it'd be great to get some more crossover assets instead.