I did think about soulless Sam a lot when I wrote this, trying to wrap my head around whether he would keep it. In the end, it made sense that he would, but not for the same reasons as regular old Sam did. I think that soulless Sam recognized that the message was important to his old self, and that it created a kind of bond with Dean. He said it himself, that things were better with Dean around, even if he couldn't feel the same affection and love that he used to. It would also have been a clue of sorts, yet another Thing About Sam And Dean that he could study and use to make sense of a world that kind of got turned around on him when he wasn't looking.

In short, I'm not sure exactly what his reasons were in all, but it kind of made sense to me in a weird way. :)

I'm glad you liked the rest of it!