Ummmm, blood elves and high elves ALREADY existed as separate groups during the purge, High elves of the silver hand under High elven Assassin Vereesa wind runner were the ones to primarily “kill and loot” (apparently this/Jaina’s killings were a blunder in the cutscenes) the Blood elven citizenry out of a hidden “hatred” for their perceived “traitorous” Horde equivalents in the Blood elves, made all the worse by Aethas’ general incompetence in politics/character discernment, something even Lor’themar makes a comment on at some point by pointing out that Aethas was “too young and inexperienced” to have the “high ranking position” he had, and the Purge and the bombing of Theramore and Divine bell theft which lead up to it was the proof that Lor’themar was right.