Am I the only one who doesn’t think that Jack’s decision to “call” Cas comes from the idea that if he brings Cas back, then things with Dean will get fixed – I see it more as a call for help. Okay, maybe there’s a layer of “if his husband comes back Dean won’t be mad any longer”, but I don’t think that’s his primary motivation for calling out to Castiel.
Look at the part of Kelly’s video that got the most emphasis:
Jack probably realizes/assumes that those things are connected. He’s going to be amazing – thanks to the angel on his shoulder. He probably thinks that Castiel is a fundamental part in the positive outcome in his future.
When he was born, pretty much all he knew was that Castiel would protect him, because his mother had told him. Now the video reiterates the idea – he can be good, he can be amazing, but it’s possible that that outcome is inextricably connected to Castiel’s presence as his guardian.
Now, it’s possible that Dean’s feelings towards Cas’ loss contribute to Jack’s perception that Castiel’s presence is fundamental. Dean represents the perspective that Jack’s path cannot have a positive outcome, and apparently Castiel’s death fuels that perspective.
But also, Jack has just heard Dean and Sam’s discussion, and he starts doubting that Sam might be doing this in good faith or that he can help him in general. What if Dean is right about Sam’s motivations for helping him? Jack already feels that Dean’s opinions on him make sense, he already is not confident about what Sam tells him, and now the Winchesters’ conversation brings up that there are things Sam didn’t tell him…
So Jack assumes Castiel’s presence is fundamental for a positive outcome for himself, Jack needs Castiel to “be amazing”, especially as he starts to doubt that Sam may be of actual help of him. Now Dean’s speech brings Castiel’s importance back onto the table, reminds Jack of what Castiel means, and he tries to get his help, the help of the person his mother said could help.
No Such Thing as Coincidence 