The story of The Scourge and The Lich King has always been important lore, and even though the original Lich King, Arthas, is no more, his replacement, Bolvar Fordragon, will return some time in the future. Probably not in the next expansion, and even not in the one after, but he'll be back sooner or later.
YouTuber Bruty gathered three of the most popular theories floating around the web about his return:
- An even more powerful scourge powered by the Red Dragonflight and lead by Bolvar Fordragon returns to Azeroth.
- The Burning Legion invades Azeroth at the end of Warlords of Draenor and since The Scourge were originally created and commanded by them they will awaken Bolvar and we're all going to die.
- This is probably the most likely outcome: Bolvar Fordragon didn't go completely mad at the end of Wrath of the Lich King and he and The Scourge would return as an ally against the invading Burning Legion.
Top 3 Speculations for Bolvar Fordragon [YouTube]