In late June, Microsoft announced a OneDrive for Business feature designed to help migrate local data off Windows PCs. At that time, company officials hinted this would be coming to OneDrive consumer, as well.
Microsoft's pitch to IT Pros with Known Folder Migration was to get user data off local PCs and stored in the cloud. For consumers, Microsoft's pitch is somewhat different, even though the functionality is the same.
Users who enable this feature -- either by follwing a prompt from Microsoft or manually by going into OneDrive settings, then More, then Settings and ultimately going to the Auto Save tab -- will be able to keep their information in sync better than if they store it locally and (possibly) sync it to OneDrive later.