It is actually image data that they were after for this large geospatial model. The game has quests where you scan an area (as well as the AR mode but I know dozens of people who play and no one uses it), which gives them the image and location pair. If they were just after your spatial coordinates they wouldn’t need any of the machinery around Pokemon Go - Niantic is a Google spin off (with Google as a major owner), so they’d be able to get that data a million other ways (such as how apps like Wordscapes track your location - by showing you ads).