I have no doubts that they're retcon it because that's what they do, unfortunately. However I think it's important to distinguish the Hell Dean went through and the place Sam had vanished into because, as we all remember, demons probably didn't even have contact with Lucifer while he was caged hence why Yellow Eyes had to kill nuns in some ritual in order to just speak with him. So I have no idea if they're going to address that or not.

I hate that they're dragging it out, either give us something to go on or just move on from it we don't need every single damn episode featuring the question of WHAT IS WRONG WITH SAM because that gets tired real quick.

I personally like my idea that however Sam got out of the cage it shredded his soul and other souls in hell were used to like "patch up" his own.

That would make an interested story idea, not gonna lie.