"In Pokémon Legends: Arceus, Jubilife Village will serve as the base for surveying missions. After receiving an assignment or a request and preparing for their next excursion, players will set out from the village to study one of the various open areas of the Hisui region. After they finish the survey work, players will need to return once more to prepare for their next task. We look forward to sharing more information about exploring the Hisui region soon."
Kotaku has written a piece about how they believed that Pokemon Legends is not actually an Open world game (aka BOTW) but actually a Monster Hunter type of game. Take a read of the article is you are interested in how they came to this determination. But they got a comment from the Pokemon Company that basically confirms that Pokemon Legend is not exactly the open world experience many were expecting it to be, but more a Monster Hunter style of a game. The trailers they have done so far have been trying to give off major BOTW vibes so I do question a little about misleading marketing.