You know what I just thought about? Before Sam comes back in season 6, Dean had to know that if none of them could get Sam back out, Dean would never see Sam again, not even in the afterlife. No matter where Dean ended up after he died, Sam’s soul would’ve still been in the cage with Michael and Lucifer.
everything about Soulless is horror to me and (no disrespect to Gamble) season 6 did not really paint that horror on my eyelids quite enough, so some of the implications just aren't front and center, but by god are they horrific.
on the one hand, you've got this person, Soulless, yelling that he doesn't want that soul back inside of him. he's got his own wants, his own autonomy. he's not sam, but he's not not Sam. and he's being violated.
and on the other hand, you've got sam's soul still being tortured in the cage. sam's soul, which is part of him and has its own autonomy and is beset by this horrifying-beyond-measure experience still, until they drag that soul out. and yet for some characters it's still a question of whether they should save his soul because it will be too awful to cope with once his soul and body are reunited.
but - his soul is still being tortured and is worthy of saving on its own merit too? and they just glance over the fact that if they asked his soul, he'd of course indicate he wants to be saved if it's possible (and once his body and soul are reunited, he does meld them, that is his desire and choice).
there's this sort of separation between soul and body and both are persons in their own way (and are missing something important and irreplaceable). and they have opposing opinions about what to do with... themselves. and that's messy and interesting.
and if Soulless dies? that's it, no heaven or hell or anything. he ceases to exist at all. and yeah, no heaven for sam's soul if they leave it in the cage for eternity. which honestly should be the core focus on the conversation (between dean and bobby, not Soulless himself), not how poorly he'll cope once his soul is in his body.
anyway yeah. one wonders if dean had died, and gone to heaven, if there -- outside of bodies and on the celestial plane -- he'd be able to feel sam all the way down in the cage, since they're two parts of a single whole. but that doesn't bear thinking about.