Even discounting the broader metro, there are almost 9 million people living in NYC. It's unlikely that any meaningful fraction of them could possibly get out in the time between learning we were in a nuclear confrontation, and the first consequences of that confrontation for NYC.

I’m not sure how it could possibly be useful to anyone to hear that they shouldn’t be in the place where a nuclear explosion occurs.

As a child of the 80's - that's probably where you want to be. Right in the epicenter, if you can make it. At least it'll be over quick.

I'm fairly certain that's preferable to the scenarios survivors of a large scale nuclear exchange will face in the weeks, months, and years after.

New York is actually surprisingly uninteresting as a military target.

You'd glass it if you were trying to kill US logistical capacity of course, but if you were trying to neuter a second-strike, you wouldn't really bother.