Dehaka, Deathwing, Moira Thaurissan, Ragnaros, Gul’dan, Kil’jaeden, Magni Bronzebeard, Grommash Hellscream, Maiev Shadowsong, Azshara, Shandris Feathermoon, Brann Bronzebeard, Horace Warfield, Valerian Mengsk, Samuro, blade Master, Kael’thas Sunstrider, Rexxar, Skeleton King Leoric, King Varian Wrynn, The Butcher, Gelbin Mekkatorque, Garrosh Hellscream, Tosh, Fenix, Cho’gall, Zul’jin, Aggra, Artanis, Lady Vashj, Arcturus Mengsk, Cenarius, Demoman, and The Overmind
Here is the source.
Some of these may not come out, but most of them will since the costs are already made with the sound files (the voice acting has to be the most expensive part of the heroes since they can’t easily bring in the voice actor to change or do lines like they can with an artist. Only one or two voice actors can do the voice acting while nearly any artist can update a character model).
Despite being old, it has already predicted: Jaina, Sylvanas, Thrall. Magni Bronzebeard may not be a hero, but they just use the voice file in some fashion. I’m not sure how Deathwing can come into the game.
Some are so obvious. Gul’dan has to come in if you played Warlocks in WoW or Warcraft 2. The blade master was the most popular hero in Warcraft 3, he has to come in. We already know the Diablo heroes of Skeleton King and Butcher are in the game. Fenix is a fan favorite. I’m curious how Arcturus Mengsk would be put in (I’m not a fan of the ‘prince’ son but he is coming into the game).
How would the Overmind work? Well, we already know how the Overmind will dance.