Doubt Joel is dead. As others mentioned, this is four years after the first game. After the first game, they most likely went back to the camp where the brother lives. Where Ellie would have gained an "uncle and aunt" and possibly fallen in love again.
Firefiles found out where they were and came after them, killed most of the camp, but some got away. Ellie is furious. Joel keeps trying to calm her down, wanting to keep her safe, but she is plotting revenge. Fireflies found the survivors while Ellie and Joel were out hunting. Ellie is back first having fought with Joel, angry that he doesn't want to go full on revenge mode yet. Trailer picks up in the cabin where the Fireflies caught up again and Ellie found the aftermath. Joel finds her full tilt playing guitar among the bodies of her last friends. Knowing the answer, he just wants a confirmation now and calmly asks her if she really wants it. Ellie and Joel are alone again with Joel being a support character to her this time around. Last of Us - Part two, hate story.
Firefiles found out where they were and came after them, killed most of the camp, but some got away. Ellie is furious. Joel keeps trying to calm her down, wanting to keep her safe, but she is plotting revenge. Fireflies found the survivors while Ellie and Joel were out hunting. Ellie is back first having fought with Joel, angry that he doesn't want to go full on revenge mode yet. Trailer picks up in the cabin where the Fireflies caught up again and Ellie found the aftermath. Joel finds her full tilt playing guitar among the bodies of her last friends. Knowing the answer, he just wants a confirmation now and calmly asks her if she really wants it. Ellie and Joel are alone again with Joel being a support character to her this time around. Last of Us - Part two, hate story.
