This isn’t the first time the 160th Special Operations Aviation Regiment has conducted urban training operations over a major US city. I think the last time they did it was over Houston.
Night operations over an urban area are incredibly challenging, and so require regular practice. Building a raining range isn’t exactly practical, so they simply fly over US cities. One presumes they have conducted reasonable liaison not just with the local police, but also the FAA and air traffic control facilities in the area.