This made me twitch a littleSo sounds like they are going to go with the multi-level city idea. Also I think they took some inspiration from the Special/Adventure manga here. In the Special/Adventure manga, the reason New Mauville was built (by the Trick Master's ancestor) was because he predicted Mauville City would one day get over populated which it did. So it sounds like they sort of went with the manga's idea but made it three stories tall (roof, inner city, underground (New Mauville?)) in order to hold the increased population. No wonder why they need tour guides now.
Actually in the manga, New Mauville was made to be a playland/theme park for children. Mauville was always depicted as a tourist trap entertainment town, and New Mauville was really a resort spot.
And when you consider THAT, it would make sense to have tour guides, or informational kiosks to help make it feel more like a real-world theme park.