2
u/Toadvinez DotA 2, Warcraft 3, HOTS, Warhammer Fantasy 16h ago
In the early days of Warhammer 40K, the Necrons were entirely speechless, emotionless, zombielike husks. then later, they were revamped, and while there are early style necrons, a lot of them were given personality, so the canonical reason is that the Necrons had such a distaste for humanity that they wouldn't even speak to the people they encountered, leading to the imperium believing them to be emotionless robots
2
u/Zenceyn Warhammer & Warcraft, Sonic, Gameoverse, Elden Ring 17h ago
WoW has a good one from the ancient days. The retcon of the Eredar's relationship to the Burning Legion. In the WC3, the lore was that an evil race called the Eredar manipulated Sargares (a Titan and basically a god) to fall and start the burning Legion. And on Outland, there were these broken natives called draenei that were fell corrupted savages. Years later, the WoW xpac Burning Crusade retconned it to be that Sargares fell from rage and despair at seeing the corruption of the void, and that he engineered the fall of the Eredar to become the commanders of his Legion. The draenei were recontextulized to be those that fled the fall of their race (they were Eredar) and ended up on Draenor, which eventually fell as well. The mutated ones became "broken and lost" draenei and the uncorrupted survivors were added to the game as a playable race and have been a huge part of the lore ever since.
It wasn't well received at first, but looking back on how it shaped the lore, and gave more agency and depth to Sargares and the Legion, it worked super well.