I’d actually heard that NY hospitals were expecting a decline if anything after Sept 11 because sex wasn’t really on people’s minds. Of course, that’s not based on anything more conclusive than the OP speculations but it made more intuitive sense to me.
During a blackout or a snowstorm there’s not much to do. On the other hand, though my SO wasn’t around after Sept 11, watching the news and crying doesn’t typically put me in the mood.