It is Kotaku who dispels this misunderstanding by relying in particular on a description sent by The Pokémon Company:
“In Pokémon Legends: Arceus, the village of Rusti-Cité will serve as a base for exploration missions. After receiving a mission or request and preparing for their next excursion, players will depart from the village to study one of the various open areas in the Hisui region. Once the investigative work is done, 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.“
This description is not very different from what can be read on the official site, which also highlights the presence “many areas with distinct environmentsThe problem is, these lines can also apply to any open world made up of multiple biomes.
The point is that since its announcement, Pokémon Legends: Arceus cultivates more resemblances to a Breath of the Wild (even in the composition of his jacket) with a Monster Hunter. Marketing’s insistence on “Hisui’s Region”, as in the last game video below, also spoke more of a unified open world rather than a terrain cut into separate regions. The idea of an open world was also quickly entered in the minds of commentators to “explain” the achievement of the game deemed unflattering, even for the Switch.