Since Medieval Stasis makes it so that a Magical Land will always be the same, and that 1,000 or so years in their world has the same amount of political, economic, and technological development as about five years in our world - that means that natural change happens pretty much never. Including geological shift. The continents, landmarks, etc. will remain in the exact same way they are across a span of 10,000 years, so the prophecy about the Sealed Evil in a Can in the Mountains of Shadowblood Peak will always be fulfilled without having Shadowblood Peak turn into the Shadowblood Picnic Hills thanks to erosion.