What do you mean "either way"? Your previous way didn't even mention Sylvanas. And Varian said nothing about Wrathgate when he declared war on the Horde. Hell, Chronicle v3 outright says he didn't give a shit whether Sylvanas was in on Wrathgate or not at that point. So the destruction is on him being a warmongering unhinged retard who couldn't deal with the fact that Horde recaptured Undercity before he managed to steal it from them.