“I find it hard to believe....”
It’s generally considered and legally established that it is within the a right of a lessee to sublet. It’s in with that bundle of rights a lessee has. IANAL and I sure don’t know NY law, but I’d suspect subletting cannot be denied.
I believe you can sublet but I’d assume the owner of the building has the right, and would want to know, who is in the building and would have some say in the matter.