Yes, it is a role-playing game, and part of the role you will be playing is of a person on a road trip with friends. If Square wants to really build this the right way and it looks like it does, it will include a large world with positive and negative spaces. The same type of set-up you would find going on an actual road-trip.
Do you know why a lot of games that don't necessarily need to include a jump mechanic, include one? It is because the possibility of doing something is really important to players even if they have no intention of ever going through with it. If Square built all these roads with invisible walls around them people would complain they were only hallways. By having this world be open, even though most players won't explore these areas, it gives a sense of freedom and place.
I don't consider it meaningful content, but the drive to fill everything with something absolutely leads in that direction. There is a fear of negative space in gaming. We can't just have a world, it needs to be filled with something or people start calling for it to get cut. The first thing you thought to call a game with negative space was a "walking simulator." We can't just enjoy the existing in the space it must entertain us like we are the center of its universe. This mentality leads to a lot of shallowness in design. It leads to wanting the player to save the entire world even if it is just one small issue at a time. Every problem, becomes the player's problem.
Nobody would be talking about SotC today with out its use of negative space, nobody. If shadow had the player teleport to each arena it would have been forgotten years ago. The game's significance is its negative space -the brilliant thought to not include additional npcs or enemies in the field. You cannot achieve the overwhelming sense of loneliness that game conveys if everything were small arenas or random quests. It would completely lose what made the world feel forgotten, and without that? The sense of violation being perpetrated by the player against the few inhabitants of that world would have disappeared. The game would be forgettable.