retcon of mary's deal? wait can you expand because i don't remember seeing anything about it lol. disappointed but not surprised...
so it’s not a literal retcon, i.e. Mary still makes her deal, but to my view, it’s a framing / thematic retcon.
4x03 is a double gut punch: first, the audience gets the reveal that Mary, contrary to how we’ve seen her as the sweet housewife, was born into a hunting family. we got a hint of this in 2x21 (why did Mary know Azazel?) but fully seeing Mary’s backstory re-contextualizes her as a character; no longer only the fridged wife, she was someone who knew and grew up with the supernatural. second, Azazel was only in Sam’s nursery to dose him with blood because he got ‘permission’ from Mary: he made a deal with her. Dean, and we the audience, have assumed Mary’s death as the starting point for the Winchester family tragedy, but in this ep we learn that isn’t true: it wasn’t Mary’s death, but her deal, that opened the door for Azazel and so many other horrors to later enter not just her, but John, Sam & Dean’s lives. Mary’s deal is tragic & disturbing - she had to kiss her dead possessed dad! - while also horribly understandable. Azazel killed her mom & dad, killed John, Mary just wants a husband & kids & normal life and Azazel says he can give it to her, even if she knows there will be unintended consequences down the line for her family. at the least it’s an ambiguous choice, and at most it’s the wrong one; Mary could have let John go, married another man, and still had a normal life, even if we know (and can sympathize with) why she didn’t.
then, way down the line at the end of S12, we get a glimpse at the Apocalypse World: a world where Sam & Dean were never born and so they never stopped the Apocalypse like they did in S5, leading to Lucifer and Michael fighting and destroying the world. already, I think, this framing is different from how Kripke’s era handled it. you can’t really separate Sam & Dean from the Apocalypse; it’s a family drama played out on a planet-wide scale. so no Sam & Dean = no Apocalypse. if S5 was about how Sam & Dean were fated to bring about the Apocalypse and subverted it because of their love for each other, then Apocalypse World implicitly suggests that it was the reverse: Sam & Dean were fated to stop the Apocalypse, and so their non-existence meant they weren’t there to do so.
later on in 13x14, we get this exchange between Mary & AW-Bobby:
BOBBY
Mary Campbell was a… complicated woman. Brave, but sad. Full of regret.
MARY
Let me guess. She made a bad demon deal?
BOBBY
Opposite. She didn’t make one. Lost the love of her life. Never moved on.
MARY
And Dean and Sam were never born. Bobby, I made that deal. And it—I brought my boys a lot of pain. But what happened here, in your world? Sam and Dean stopped that war in mine.
BOBBY
Then I’d say you made the right choice.
the subtext of this conversation is that while Mary’s deal might have been the spark for the fires that burned through Sam & Dean’s lives, her deal with ultimately a good choice - it led to Sam and Dean being heroes and saving the world. the ambiguity that was there in Kripke’s era is dropped for something emotionally simpler and less tragic.
in Kripke’s era, Sam and Dean were chosen, and being chosen meant being cursed. they won by fighting as hard as they could against their fates, and true to Kripke’s humanism, it was Sam & Dean’s love for each other that saved the world. in Dabb’s era, while being chosen may mean suffering and hardship, it also means being a hero. arguably I’d say being chosen is a gift, even if it’s a painful one, if one looks at how powers / helping the world is talked about with Jack, Patience, etc.
neither of these two framings is “right,” per se, but imo they are two very different framings of Mary’s deal.