I went through this checking things a bit back. Found a list showing that not ALL Nissan come with the chipkey but it's according to what was on the list. Nissan dealers let you think ALL have them to get unnecessary programming charges in some cases. It's the new world Trump way.
Don't know either if these are like Fords in that if you respond BEFORE you have the need you can program keys yourself, you have to have two known good ones and a blanked chip but edge cut third, owner manual has a halfway simple procedure for programming a third yourself if you have the two. If you wait until you lose one you are out of luck though, the programming needs TWO known good inputs before it will release to do the third one.
I drive older cars and don't theft protect as they are dog cars. The Ford chip easily removes from the key to then bind it within an inch of the transceiver ring and then you can buy keys for $2 all day long as the chip is right there and keep your mouth shut. You still have to have a key to take car just like oldschool. They can bash the ignition cylinder out of it obviously, I say get with it, the car not worth the effort. I don't think Nissan chips come out of the key though. Haven't tried yet anyway.