I’ve always wondered this and please correct me if I am wrong, I’m only going by how the old game felt set up and have no factual proof. Didn’t the old writing team read LOTR and played DnD? With having all the parallels with Humans vs Orcs, and Blackrock Mountain. Then WC3 came in and the DnD aspect came in with infinite chaotic demons from the Twisting Nether(the Abyss), and Night Elves being based off Drow. Unique things being that the hero falls being that of Arthas. The Orcs trying to regain their morality, and are not just monsters.
Then the new writing team came in and just went for whatever was flavored of the year. First Lovecraft took over, then Game of Thrones, now this Game of Lovecraft sigh. So many retcons, making everything confusing just to go for the flavor of the year it seems.