Where do Gloranthan prophecies come from? We are told the gods, like the human unconscious, do not recognize the distinction between past, present and "future." But not all divinations are literally true. They require expert interpretation. Perhaps these divinations function as "prophecy" until someone emerges to decode them correctly.
Or perhaps all the "prophecies" we have are not magically supported at all but are instead consciously constructed as wish fulfillment, propaganda or to serve some other goal. This would make me a little sad. While I'm sure plenty of mystagogues actively promote fake visions of the future, it seems like a waste to attribute the entire Hero Wars complex to this kind of activity. Moreover, in a world where the gods are real etc., it strikes me as extremely dangerous to lie like this . . . sooner or later, the right people will find out and you will get in big trouble.
Either way, where does all the foreshadowing come from? Who sells it? How is it made? Where are the margins?