He's dead, and he's going to stay dead as confirmed by Bungie. Honestly, I'm glad he died from an emotional aspect. His death gave me the motivation and satisfaction of progressing and completing Forsaken in my quest to avenge him. Plus, he went out in one of the most badass ways I've seen a character die in a video game in recent memory. Cayde is home with Ace, take comfort in that he is finally reunited with his son.