Wikidata can (and probably will) store information
about each moon of
Uranus, e.g., its mass. It does probably not make sense to store the mass of
"Moons of Uranus" if there is such an article. It does not help to know that
the article "Moons on Uranus" also talks (among other things) about some
moon that has a particular mass: you need to know what *exactly* you are
talking about to exploit this data. An article on "Moons of Uranus" could
still (eventually) embed Wikidata data to improve its display, but this data
must refer to individual moons, not to the article as a whole.
The problem I see is that you have no definition to which real object
the data are tied. We agree that the problem is not the interwiki
links per se. It is what results from it. How do we tie data to a
wikidata page when we don't know what it is about?