No. It's a rifle or shotgun which accepts a detachable magazine AND one other feature.
For instance, a semi-automatic rifle or shotgun with any kind of internal magazine, such as a tube underneath the barrel or in the stock, is perfectly legal in all cases. One with a detachable magazine and at least one of the following would now be considered as an assault weapon:
a folding or telescoping stock
a pistol grip
a bayonet mount
a flash suppressor or barrel threaded to receive one
a grenade launcher
a thumbhole stock
a second handgrip or protruding grip to be held by the non-firing hand
I own several semi's in various calibres and none of mine would be illegal in New York. How many do you have which would be? At one time, I owned an M-1 Carbine with a folding stock and a pistol grip. It would be. It would also have been classified as an assault weapon under the old federal law.