The less-chaotic desert is growing, and the "sound" of dhar is dipping, but so slowly it can't be registered. Like a finite number being subtracted from infinity. They've...what, inverted the rune of Valaya? I don't think just turning it to Valaya's Vengeance would do this; this effect is growing. Divine magic doing the purifying says it almost certainly has to do with that rune, though. My guess is they're trying to kill the Chaos Wastes. No wonder the local tribe has fallen from favor/thinks they have; Karag Dum is literally undoing the "blessings" laden on the chaos wastes, and they cant stop it.