Having lived my entire life in the Netherlands, I find that, as a general rule, the Dutch tend to over-organize many things, including Nature. I don’t see this as a good or bad quality. There is just a lot organizing of everything going on. For example, the municipality of Amsterdam has a bilingual database of every single tree the city maintains, currently at 214k trees.
Some relatively low managed areas have wild trees, like Amsterdamse bos (a planted forest) and Vliegenbos (also a planted forest). If that is the location of the observation wild can be considered. So I believe it is reasonable to at first assume that almost all the trees in the city of Amsterdam are cultivated. If the observer provides additional info in a note or comment that will be considered, of course. Additionally, the municipality database seems far more reliable for research purposes than iNaturalist data.
What would curators prefer? Just a comment and marking it as a not-wild and keeping it at Unknown? Or giving it the best ID one can come up with along with the comment and DQA not-wild as I did on this observation? Or something else?
(I read completely Should I tag city trees as captive? and The category of “cultivated” is problematic for plants in urban landscapes partly)