[In theory, yes, eventually they'll have to return. But Castiel's come across a few people, like Philip, who have been here for years. It may not matter so long as they make it back home at one point or another, but...]
We pull the plug, or this place sends us back and takes our memories in the process.
[Which means he'll return and make the same mistakes he's already been warned about here. Dean's already told him how the plan failed the first time, and as far as research goes, Castiel hasn't come across any leads on how to retain his memories.
It's a thought that's been wearing on him ever since Dean broke the news.]
video;
We pull the plug, or this place sends us back and takes our memories in the process.
[Which means he'll return and make the same mistakes he's already been warned about here. Dean's already told him how the plan failed the first time, and as far as research goes, Castiel hasn't come across any leads on how to retain his memories.
It's a thought that's been wearing on him ever since Dean broke the news.]