I think many times there is the need to be a bit vague about prophecies because otherwise they would be spoilers....Of course i understand how can this be annoying, specially when being upfront about the info could have avoided unneccesary drama.
I have a minor character that can see the future and tells prophecies in a straightfoward way, but the irony is that she takes this knowledge for granted so she ends up being unintentionally vague. Example: answering questions before the person asks, which could be enough for the asker (if it doesnt confuse them in the first place), but the comic readers would speculate on what was the question they were gonna ask to her.