I don’t have the book myself, but in the Unoffical Playable Sethrak Discussion Thread someone said that the Sethrak were mentioned in the Vol’dun section and said the following:
"The Devoted are in control of the temple of Sethraliss and rebuilding, Sethrak society are no longer divided. Although many of the sethrak from both sides that feel the scars of the civil war is too great started to follow Akunda, the loa of renewal and new beginnings after they established contact with the trolls at Akunda’s temple.
Some sethrak also live with the trolls and tortollans at the temple of Kimbul. They also have friendly contact with the vulpera but some time is still required to fully mend their relationship due to history. The scorched sand outpost was abandoned after the exiles there was welcomed back by Talanji, and the vulpera plan to make it a joint trading outpost between them and the sethrak."