This is the same writer who had a character go to heaven and then get resurrected by "Ezekiel" while heaven was locked down and inaccessible to souls or angels. He's definitely better about canon than a bunch of the Supernatural writers, but he's messed up before. (That said, I'm among those who think the canon departures are going to be at least mostly intentional, though I wouldn't be shocked if something slips by.)