Maybe it is not a publicity stunt, but maybe it is meant to be an object lesson.
It is an object lesson - right out of Rules For Radicals. Make them live up to their own rules/values. Or put another way, spread the pain so all will feel it. The more pain NYC feels, the more pressure they will put on their elected officials to actually fix the problem, as opposed to dismissing it as ‘that’s a problem for Texas.’