They did get criticized for it, but I think that was a little too much. I don't like Golden's writing style, but the abuse she got was not called for and anyone involved should have been ashamed of themselves.
A Light vs Void expansion could be something that involves the Sin'dorei and the Sunwell quite heavily, but we don't know whether that would involve the Elves losing the Sunwell again. Their are ways Blizzard could tell that story and make Silvermoon far more "Sunfury" like, with Blood and Fel Crystals dotted around and a strong focus on Arcane magic, but it's whether they'd want to retell that story again.
I mean, to take on the Void would likely involve the Void Elves, but I reckon, their counterpart - the Shal'dorei, should be the Horde leaders, since Suramar had Void-Arcane Elementals dotted around the Nighthold.
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Ahh I see what you mean.
I reckon it still needs to have that "element" of Thalassian though. Maybe some Elven Sanctums, but with purple, gold and blue colours instead of red, white and gold.