The phrase "to update the map" means to make changes to a visual representation of an area, such as adding new information or correcting existing information. Full definition
The findings may help explain how the brain maintains a constantly updated map of our surroundings. (sciencemag.org)
This function updates a map with new listings as you travel — perfect for a client to view as you drive them around a neighborhood. (speakingofrealestate.blogs.realtor.org)
We are updating this map as more information comes in about other enrollment opportunities. (familiesempowered.org)