My bet is if they correspond to astronomy or astrology, then it would indicate a constellation, a nebula, planet or star that fell, either in pattern over the horizon, or literally through an act of gravity as a meteorite or falling star does, out of order or chain of command.
It could indicate Lucifer, king of Tyre falling out of power.
It could indicate Venus, again, possibly an astronomical event.
It could indicate a loss of enthusiasm or joy, it was downcast or fallen in emotional expression, or indicate madness befell a lord of reason.
I agree, ask the fallen angels themselves. They’ll give you a true answer.