[heed]

I don’t know what OP meant by “steal” but the complicated thing with using OSM data as a mapmaker is that if you “derive” any other data source with it you have to make it available which means (as I understand it) you have to contribute it back to OSM.

If TomTom was planning on conflating OSM data with other sources then in theory it hurts their business model because they will potentially have to make their entire map (or large parts of it) freely available in OSM.

If they can somehow set up clean room conditions and keep all their other data sources physically separated from the OSM data then it might be avoided, but then how do you do the map conflation? And that would certainly impact how quickly they can make updates.

Maybe they came up with some clever way to avoid having to contribute data back to OSM and that’s what OP means by “steal.”