It is not state law that governs what you can do with your condo as much as it is the building's master deed and bylaws. Therefore, what is allowed in NY has no bearing on what is allowed in your building in NJ.
I have recently done extensive research on this issue for a client and NJ courts have upheld such restrictions in almost all cases. Condo associations do not want their buildings appearing to be hotel-like; they want stability and a more home-like environment. The courts have said that these are valid goals of a condo community and have said that short-term rentals can be restricted.
To answer your question, what would happen is that you would probably receive a cease and desist letter once the association found out your unit was on Airbnb.
Actively practicing law in Texas. Inactive licenses in Arizona and Georgia. All answers are general in nature and no attorney/client relationship exists in this forum.