WINNER!
Explanation:
Clue #1:
Are you afraid of what you'll hear?
Afraid I'll speak the fate you fear?
Not Jon! Not Taylor!
Not Saxon! Not Shore!
Don't worry, child, I know my job,
You'll learn to laugh, if first you sob.
—> This is the Storting Hat's song from Harry Potter and the Cursed Child (modified here and there to fit the game). Which is shit plot wise, but it's about a (wait for it) cursed child, as SSOASS is. Jon (Schaffer), Taylor (Swift), Saxon (the band) and (Howard) Shore all wrote songs / pieces titled The Prophecy (or simply Prophecy in Iced Earth's case), but obviously those weren't "The Prophecy"s you were looking for.
Clue #2:
The song you're looking for has a quite uncommon structure for an Iron Maiden song, in that it is not circular - although you
do find a circular structure in there. It also kinda starts, but definitely does not end, like you would expect given the songwriting pair.
—> First sentence is self-explanatory. If you take out the intro and the coda, the song has a circular structure, as many Iron Maiden songs do: the heavy riff, verse 1, bridge, chorus, solos, verse 2, bridge, chorus, fade out riff which is the first heavy riff repeated. Many songs Dave Murray has written start with a slow intro with solo guitar over an arpeggio (as The Prophecy does), but definitely do not usually end with a slow acoustic coda (let alone fading out).
Clue #3:
The song you're looking for is not a title track, but it mentions the title of
another Iron Maiden album... with a very little variant. And, this time verbatim, of an Iron Maiden song too.
—> Obviously not the title track, but it mentions the title of Live After Death (almost verbatim) and Purgatory (verbatim): "
Purgatory reckons - Souls lost forever /
Life after death - or heaven hereafter".
Bonus clue: you didn't mention the songwriting pair yet.
—> Explains itself. The Murray / Harris pair hadn't been mentioned yet.