User blog comment:EmpyreanSmoke/Supernatural Q&A/@comment-96.91.247.202-20150901175332/@comment-24834479-20150903172550

I don't think that they were able to pick it up before Castiel aported them.

Beings higher than them such as Eve, Leviathans, Archangels, etc.

I'm not sure about that one; I don't think it was written.

It's possible that monsters or able to evolve, or she made another beta version.

I hope we get to dwell into Cole a little more, so I'll say that it is likely we'll see what his father was.