Bing, California has similar language in their restriction of knives. However, it's widely understood that all the folders sold at the Walmart and Big5 stores in California can be carried concealed legally. There is a defined distinction between switch blades (and the like) and legal assisted opening knives. The difference is defined in the Penal Code and further defined in the case law.

In this New York situation, I believe it is the DA that is the difference. I believe the DA would get schooled in court, but in the mean time the DA gets to up his stats on arrests in order to advance politically. "Hey, the new DA surely is making us safe with the increased arrests." If he later gets schooled in court, it will only make him look even better politically because that would simply mean more press for his cause.