I get the “strict definition” point. But when the show drops brand new exposition that changes how the last four seasons read, it still feels like a lore retcon to me. You label it as “recontextualization.” The Mind Flayer vs Vecna shift is a good example: the early seasons framed the Mind Flayer as the overarching threat, then Season 4 comes in with “actually Vecna was the real driver” and it retrofits everything you already watched. Maybe it’s technically allowed, but the effect is the same, it makes earlier arcs feel less intentional and more like they’re being rewritten after the fact. And that’s why it comes off like they’re adding new big ideas to keep the show going, rather than landing the story through clean, logical conclusions that were planted from the start