That’s the fun thing about these quotes though. They are there to be part of the void’s endless possible outcomes. They don’t necessarily have to come true, but it always allows the writers to go back and reference them.
It’s just good ol’ fun.
To OP:
They are building up Elune to take the villain bat it seems. Both the void and the brokers (Death) have made remarks of Elune not being this peaceful goddess.
There have been a few times now were they have remarked that she is not trustworthy.
However, if I’m not mistaken, Elune is said to have Silver eyes.
This has lead to a majority of people speculating that this will be Ysera- somehow.
Her being a main character within Ardenweald also raises speculation into this, as she is labeled the Winter Queen’s sister’s “pet.”
If Elune isn’t trustworthy, then her “pet” could “disguises treachery.”
The quote itself hasn’t been made clear enough, along the lines of the King of Diamonds being made into a pawn, so it probably hasn’t come to past.
Another interesting bit, in the Gilmore of the Shadowlands book, Ysera is stated to have been saved by the Winter Queen using part of her “essence.” This connection has tied Ysera to Ardenweald and she shares the same fate as the Night Fae now.
This could lead into an interesting story with the Winter Queen and her relationship with the Jailer…
“The boy-king serves at the master’s table. Three lies will he offer you.”
This too is speculated to be Anduin, he is often referred to be the “boy-king” (little lion) and in the Archon’s Sigil cinematic, they really emphasis the word “King” when referring to Anduin aswell.
Some people believe that this was one of his three lies, to gain an audience with the Archon, but that’s pretty slim.
Again, this doesn’t seem like this has come true just yet.
(Or even will- again Voids see possibilities, these are just for fun.)