Brandon's first response to the question about new threads/plots was that these last 3 novels were to be about closing up the loopholes and so new new threads. But then Brandon said "Mostly."

I wonder what new plotline Brandon had in mind when he changed his answer to "mostly."

While still a possibility, it is highly unlikely that we see an army of channelers attacking at Demandred's command from the Aisle of Madmen because this would be starting a new plot/thread.

On the other hand, we've seen several references to the Sharans, including the scene in KoD with the silk worm traders and including all of Noal's tellings. Not to mention Graendal and Sammael's interactions much earlier in the series. I wouldn't rule out the Sharans playing a role in the next book or two.