One thing that happened when Pokemon Go got popular is that people (users) were conducting vandalism, in the sense that many pokemon figures were added to the main map of OSM. People have to work really hard to remove these, and they might burn out on this. There is already a lot of vandalism, like people adding their friends drinking shed, or whatever they think of as funny.
Another thing that already happens with volunteers, is people thinking their working area is "their area", while no such concept exists. This can already give a lot of friction among volunteers. I can imagine if billions in money are at stake, big companies with a massive crowd of emplyees might want to really grab those working areas and drown out volunteers. If that gets a big problem, volunteers that were active for years might drop out.