Yes, correct. And JFK tower tells people to fly 500.
At or below 500 is the norm. And I don't know who can stay at 500ft and not go up a few feet into the B. I always fly it 450ft.
And not all aircraft talk to the tower. The past month I have done the transition three times and three times I have had tower tell advise me of traffic they are not in contact with. And that is just south at the rockaways.