BTW, maybe related:
https://meta.wikimedia.org/wiki/Grants:IdeaLab/OSMdata:_a_Wikidata-like_edit...
I added the following to the talk page of that article: Nodes/Ways/Relations
Nodes, Ways and Relations. Those are the primitives we have currently in OSM. The way I see it, it would be interesting to have something like Adresses, Streets, Public_transport_stops, Bus/Tram/Train lines, Route_variations, etc.
These "Primitives" would contain pointers to the N, W and R primitives that are currently used and that were previously used as componenets of the higher level Primitives. It's these higher level primitives that may make sense to store in a WD instance.
In a way we already do parts of this using relations. What relations don't offer is the historic part of the data. Digging into the history of OSM primitives is a very hard thing to do. Overpass API solves part of that problem.
For the above proposal it's important to keep the WD instance up-to-date with the minutely diffs.
At the moment the best way to "marry" OSM and WD is by adding wikidata and *:wikidata to the OSM primitives. There is still a lot work to be done there.
If such a WD instance dedicated to OSM ever takes hold, it may be interesting to cross link Wikidata to/from it.
Polyglot