For those who don't, he was a troll pirate in Thousand Needles after the Cataclysm, and he was killed by the player, and then resurrected through voodoo by his wife, with the help of the player.
Vol'jin was only recently made Warchief, barely had any character development, did nothing in WoD and died after the Broken Shore. Do you think we will see him resurrected through voodoo magic? It certainly is possible, so if we can so easily resurrect some no-name no-good pirate, why wouldn't we do it for Vol'jin? I think it would give his character some edge, turning him into someone who came back from the realm of the dead through voodoo magic. If left like this, his death just feels lame.