Thought One Piece had a thread about this but his was about Vegapunk and the only other Sabo thread was Calcifier's speculating about Ace's last words during the war. I shorten it as much as I could but if people still confused about it I'll edit the whole break down again into the first post.
So here it is the undeniable proof Sabo is alive enjoy!
Bottom line is if you reread the Sabo Flash Back you will see the only logical person that could be for Dragon and or Dragon's crew to put forth effort to save is Sabo. It was a flashback within a flashback at the time the narrator introducing us "On the night of the celestial dragon arrival" that right there is saying yeah this is Sabo. When you read One Piece you should take what ever the narrator says in those square chat boxes into great consideration. It's the same as when Ace vs Blackbeard, the chapter ended without us knowing who won. But the narrator said "This battle between these 2 pirates will be known as the trigger for a very big incident in the coming future." Which was the war 100 chapters later.
The page above is the hard spoken proof of Sabo alive, not to be taken as "maybe,might be alive, I believe" ***** shit.
How is that answered? It was the first time we had a flashback within a flashback, once you start connecting it to the events that happen on the night of the fire then to the celestial dragon arrival day you will see the obvious.
Only 2 other choices are there for those anti-Sabo ain't alive to say, besides not being confirmed yet. Is that Dragon Saved Bluejam the only other named character within the Fire besides Sabo who disappeared that day, which is retarded. The other is that "It could be a random person he saved from the fire." Ok Oda drew us a flashback within a flashback for the first time showing Panels of Dragon's boat and his crew on Zoro's island for Dragon to save a random no named character. When Sabo was foreshadowed by Ace as one of his final words before his death. And his death played a key role already for Luffy and Ace since nobody knew he was saved by Dragon. As well on the night of the fire Sabo literally had a emotional break down in front of Dragon and for the first time in the whole ****ing manga we see Dragon with a shock expression or a expression different from his regular "Can't beat me *****" look.