I didn't think of that, but I can see how it would make sense. I took it as a reassurance. Dean has 発言しました that Winchesters are cursed. So, knowing that Winchesters are actually a good force, is a weight off Dean and Sam's shoulders. Also, it gives them something to be proud of. For myself, as an audience member, I hope they were implying that the boys won't be be dying off at the end of the season. Of course it could be foreshadowing the death of one of them anyway. (Although we know there's a season 9, so if one of them dies than we'll get them back as always.)
The way Dean used to spread it around I wouldn't be surprised if he already had one! We know he's not always "safe" as he asked Lisa if Ben was his and fathered the "amazon" child - so there could be a non dead skeleton in his closet!! :-)
