I'm so anti-spoilers I don't even own a TV.
If I'm watching a trailer and they start spoiling the movie I stop the trailer. Is ok that lots of people like to be spoiled and all but I don't see nothing wrong in putting a warning or tags just in case, and it should be the norm
I'm anti-spoiler as well, but I don't see how saying "In this game, you're a Dad of War" is much of a spoiler. We don't know what exactly he gets up to in Scandanavia (beyond scattering his wife's ashes). I hope it involves poking out Odin's other eye in the first stage, so they know who Kratos is. We'll encounter Thor in Dad of War 2.