>>40205541The game informer article say exactly that actualy.
Gamefreak has a team entirely dedicated to making clothing for the player character AND the NPCs, because they want all towns to have NPCs that represent that town's style and athmosphere.
So the NPCs you see in the big city will dress like city people, while their variations in the smaller rural towns will be dressed like the kind of people you'd meet in a place like that.