How does rebirth work for arahant and non-arahants?
Indeed puthujjanas knows that it makes no sense to ask where a fire go once it is put out, unless those puthujjana managed to create a fantasy where they deify fire..., so the buddha says that It makes zero senses to ask where an arhant goes, or if an arhant exists after parinibbana, by creating a parallel between fire and craving (or fire and existence).
Same thing about the stupidity of trying to figure the non-existence of a buddha.

It is craving that is the path to vedana, the 5 aggregates, birth, dukkha and all that stuff, so once there is no craving, well there is nothing left and there cannot be birth again.