Originally Posted by
Seabass123
Well it was over a gradual amount of time, but eventually at some point he did leave and that was the start of his falling. It would seem to me quite possible that Sargeras fought with the other Titans on Azeroth against the Old Gods, insprisoned them, set up/repaired their facilities (ie, Uldum), and sometime during that timeframe, Sargeras had left. He was already on the path, and the battle with the Old Gods was the tipping point and he departed. None of the Dragon Aspects received a blessing from Sargeras, while Eonar gave blessings to 2 aspects. Perhaps he left before the Dragon Aspects were a "thing" and blessed by the Aspects?
Is it "rumoured" though? I don't think so. The story of the fallen Titan comes from the Prophecy of C'thun, which details his resurrection from this battle with a Titan, while it is uncertain whether the Titan was vanquished, but he/she did fall. So the "falling" is for certain while "vanquished" is uncertain..there is no 'rumour' here