Actually, I agree with the idea that we may get an overlapping moment in ToM that brings Graendal back, briefly. BS suggested as much. And I really love the idea that this leads to Arangar bringing down Mesaana. I think it's logical and would read well on the page.

DomA's idea makes total sense - a BA comes into the Little Tower and reveals a weave never seen before, and it's a weave that could be used to root out Arangar! If you remember, Mesaana was angry at Arangar for Egwene's capture; Messy was sure that the rebellion would collapse. So not only is Arangar suddenly much less useful, but Arangar is the only other person who can really tamper with Mesaana's AS power base. It makes a lot of sense to just oust Arangar from the place, if not remove her from competition outright. And all Mesaana has to do is show her BA servants an AoL weave...

RJ must've had a point in showing us that Arangar learns Mesaana's location from Graendal. Graendal also has vast contacts, so it makes sense that this super-smart woman could puzzle it out. It all fits.

Etzel, however, is definitely 100% right on Arangar's murder victims. Both women were killed with saidin, remember?