Whatever. He could be trolling.
Yea, my feeling is that he just gave an answer to appease the interviewer. Chase isn't exactly known for being a straight shooter and for him to admit such a thing really goes against his storytelling philosophy. He's tired of having been asked the same question for seven years - he was tired of it at the time it aired! I expect this won't end the questions though.
Whether Tony died at the end or not is inconsequential to his journey over the show. Really the whole fan speculation is the byproduct of our internet culture that feels the need to "peel back the layers" and look for things that don't really exist. If you've read that
multipage article written by a fan that's been floating around the internet for years that lays out why Tony supposedly "died," David Chase would have to be the smartest man on earth to have put that all together over the course of the show.
This trend of the audience needing to "find the answers" really is a bad habit; one that nearly destroyed True Detective and one that I'm worried will harm one of my new favorite shows: The Leftovers (which I always want to call The Departed instead). Writers owe the fans nothing - certainly not closure.
Just sit back and enjoy the ride. No need to always get a microscope out.
...which reminds me that I need to re-watch all of The Sopranos for the fourth or fifth time.