Sounds like you don’t actually know much about it. This is a map dataset, they have no way of tracking people once it is independently implemented. They also could have just released a map app using OSM and collected data from that, there was nothing stopping them.
They explained in their FAQ why this is a separate project:
Overture is a data-centric map project, not a community of individual map editors. Therefore, Overture is intended to be complementary to OSM. We combine OSM with other sources to produce new open map data sets. Overture data will be available for use by the OpenStreetMap community under compatible open data licenses. Overture members are encouraged to contribute to OSM directly.