"We're more of the love, blood, and rhetoric school. Well, we can do you blood and love without the rhetoric, and we can do you blood and rhetoric without the love, and we can do you all three concurrent or consecutive. But we can't give you love and rhetoric without the blood. Blood is compulsory. They're all blood, you see." ― Tom Stoppard, Rosencrantz and Guildenstern are Dead
Huh, the more you know. Didn't remember that bit.
Honestly this retcon has so much more storytelling in it, and ties in with stuff that was in MoP anyway. i.e. When Wrathion ate Lei Shen's heart he had that weird possession experience and started ranting about someone being "gone" which we can now recognize as the Titans themselves since their spirits are in the Keepers, etc."
Which also means Wrathion has Aman'Thul's power. But yeah, this is *much* better, and awesome to imagine.
Lei Shen's reported death to old age may have been what the Pandaren thought happened, as they wrote that particular bit of history. They may not have been privy to Lei Shen's trip to Uldum and the nature of his defeat there, and I doubt the Mogu would've wanted to make it common knowledge.
"We're more of the love, blood, and rhetoric school. Well, we can do you blood and love without the rhetoric, and we can do you blood and rhetoric without the love, and we can do you all three concurrent or consecutive. But we can't give you love and rhetoric without the blood. Blood is compulsory. They're all blood, you see." ― Tom Stoppard, Rosencrantz and Guildenstern are Dead