Best guess? Consolidating their power, preparing to assault the remaining Lords of Sin. They caught the previous ones by surprise, and those were the weakest of the Seven. Not necessarily in terms of personal strength or magical ability, but in the resources that were available to them. In order to take down the remaining Lords of Sin, they would need to be far, far stronger and smarter than they were when they began this endeavour.
By comparison to Kale, Kelerak or Daven; the Twin Kingdoms of Zeland and Orland have forces that are far more entrenched and, crucially, aware of the very real enemy in the west. Then you have Wawmar - practically unassailable by conventional forces, and it would take an incarnation avatar of an Assassination God or something to slip through unnoticed and triumph there. Farland too is similarly defended, albeit more by virtue of being accessible from the west only through a very few routes that would be easy to keep under heavy guard.