In my mind, there are 2 conclusions you could come to: 1) There is an actual plausible nuclear threat, or 2) There is some benefit to making people irrationally fearful.
There is also the more benign: 3) a group of employees whose job it is to think up and produce these videos thought it should be made.
How about option 4: we unfortunately live in a world with nuclear weapons which are controlled by humans and humans are not always predictable . Its good practice to communicate the emergency plan well in advance of needing it.
Yeah, it's literally the NYC Office of Emergency Management. Their whole jam is being prepared for disasters. NYC has seen enough of them already that they need an agency that can respond faster and more fit to the city's needs than FEMA.
Maybe but that job requires a basic understanding of public perception, so they must know how it could be perceived, yet they did nothing to account for that.
Reminding people that the sword of damocles is still hanging there is a good way to build support for solutions.
Upon review of Cold War history and the state of our media, I'd be inclined to select conclusion #2 at the moment.
I imagine it might persuade people to support Ukraine and pay attention to what's happening over there.