I don't think in the context of an RPG this is true. If the GM hands the player the dungeon map, do they suddenly have more agency? I don't think they do (in the sense of what agency generally means in an RPG). Again there seems to be a divide here, I would point people to the Monte Cook article I posted, because it is a closer use of the term to how I and I think how people like
@FrogReaver are using it. For me, if the players make choices in the campaign, that lead their character to obtain that map in setting, so they can then exploit it, that is agency. On the other hand, if the GM just hands the map to the players soley to give them more information (not because of something that happened in game), that info doesn't make their choices meaningful. It doesn't enhance agency. It simply shifts their POV from first person to something else. A shift in POV is not an expansion of agency