TV’s Frink said:
And again, are we allowing the novel for TFA into evidence?
Absolutely! In fact, let’s admit some into evidence right now!
From the TFA novel:
“Kylo Ren, I watched the Galactic Empire rise, and then fall. The gullible prattle on about the triumph of truth and justice, of individualism and free will. As if such things were solid and real instead of simple subjective judgments. The historians have it all wrong. It was neither poor strategy nor arrogance that brought down the Empire. You know too well what did.”
Ren nodded once. “Sentiment.”
“Yes. Such a simple thing. Such a foolish error of judgment. A momentary lapse in an otherwise exemplary life. Had Lord Vader not succumbed to emotion at the crucial moment — had the father killed the son — the Empire would have prevailed. And there would be no threat of Skywalker’s return today.”
So there we have it. The “Snoke Lied to Ren About Darth Vader Turning Back to the Light” theory goes down the drain.