The final episode of the Sopranos was a lovely dramatisation of 'The Schrödinger's Cat' scenario - which explores the atomic theory of something existing in a 'quantum superposition' of possible states (ie both dead or alive at the same time)
David Chase gave us a scenario which could equally result in Tony's Death or Tony's continued existence but, by not resolving the question Tony remains with us - an equally living/dead character - in a remarkable ending to a wonderful series.
Is Tony Dead? - Bobby said being hit was like 'switching off a light' - Leotardo had experienced this at the gas station.
Were we seeing Tony's own light switching off as the man emerged again from the restroom and blew him away.
Is Tony alive? - Were we seeing the rest of Tony's life as it must be, every stranger a person to be watched, every door-opening an event to be nervously anticipated?
We don't know.I hope there will never be a movie or anything more from Tony so that this moment of narrative closing can live/die on as a perfect/frustrating enigma.
Bye Tony, it's been emotional.