So there were a lot of callbacks to different scenes in 8.17 - the thousands of dead Deans to the charred wings Cas left in Heaven, Cas’s beat down of Dean similar to Samifer’s beat down of Dean, Dean using “need” to reach Cas, etc etc.
There was also, I think, a lot of similarity to how Meg and Jo are framed in their dying episode (which is almost funny, considering Meg killed her.)
Fans, overall, did not like Jo, and from what I’ve read a lot of that stemmed from the way she was written as a love interest, as opposed to a character who was also a love interest. [I mean, don’t get me wrong, any of the women potential love interests were hated on something fierce, especially in s1-3, so fans probably weren’t ready to like her anyways. But even though she did have her own specific motives and desires, she is framed around Dean’s interest in her. Twice she points out she wants to hunt because of her dad - in 2.6 No Exit and 7.4 Defending Your Life - but the show still puts emphasis on Dean’s role in having her hunt, and it never shows her as an independent hunter. When she is off hunting on her own we actually see she is back to working in a bar (2.14), and then later we only see her when she is also hunting with Ellen (5.2, 5.10) even though part of her character was her desire to get out from under her mom’s control, or her hunting is an off-hand comment (2.21, 6.17).] But the writers gave her a “redemption” from her crush on Dean by having her reject his advances/last night on Earth speech. See, she’s more than just a love interest, the writers say. And then they killed her. She died saving Dean (she got hurt from the hellhound because of putting herself in the way to protect Dean) and ETA: didn’t even get to actually blow up the store. But before that we get a touching scene between the two of them of Dean and Jo saying goodbye.
Meg, my thorny beauty, is a villain. She’s killed family friends, she’s aimed to trap John twice, she sexually assaults both Sam and Jo, she possesses people including Sam, she helps Lucifer…Meg is a villain. And since she’s the only one alive since S1, she’s a damn good villain. But Meg, as she points out, is also “a little good” (8.17). What started as a way to say fuck-you to Crowley (because, to be clear, that’s her cause after Lucifer dies, destroying Crowley, and she’s wiling to work with the Winchesters to do it) turns into a general liking of Cas. (To clarify, I think she wanted to fuck Clarence, and then she started to like him, and then all of a sudden in 8.17 he was her unicorn which WTH.) She isn’t redeemed and she doesn’t want to be, but she does consider herself an ally (she wasn’t surprised but she was disappointed the Winchesters never went after her during her torture tour with Crowley).
So in her death episode, we have her helping the Winchesters, having a special talk with her crush where her crush is trying to comfort her, sacrificing herself for her crush even though it made just as much sense to frame the scene as her sacrificing herself to fuck over her enemy, and dies so the Winchesters (and Cas) can get away. She dies and ends the speculation of if the Megstiel relationship was going to go somewhere. And though it comes from opposite directions, as soon as we see the scene of her planning a hook-up with Cas (just like as soon as we saw the scene of Jo rejecting Dean because of her self-worth), we knew she was going to die.
And it’s pretty fucking shitty that we once again have a woman character’s death framed as a love interest instead of what she really is, which is a hunter and a demon who are trying to stop their enemy from winning, even if it means their life.