I think they were around for a while tbh. They are lvl 58 when you start after all and they all have vague memories of the first war against the Primalists (many of them seem to have a faint memory of Raszageth they cannot pin down). We do not know the timeline but I don't think the war against the Primalists happened immediately before the Sundering; I'd assume Neltharion was not mad yet.