I think Prophecies are one of the hard problems of GM-ing. There are a number of things that collide:
- Player agency
- the players taking out the Big Bad Evil Guy way earlier then expected, thus ruining the story. You would have nothing to replace it with
- that the prophecy is basically a spoiler
Now I do have an answer to dealing with this and I am mostly writing this Question to document it for others. But I am still interested if you have any other/similar tricks to deal with it?