I dunno, I was under the impression that the place had grown significantly and now had AM families, merchants and others there too. Sure, it is probably more secure than Tar Valon, but at the same time the Seanchan can now travel. They can basically open several gateways all over the BT during the night for example and basically start mass bombardment before the Asha'man have any idea what is even happening. Sure, they would wake up and start fighting back but odds are that in a well executed attack, a lot of them would die in that first volley of fireballs from the damane.



On the other hand, they believe that Rand&WT are allies, and that the WT attack would turn Rand against them fully. Tuon states exactly that when the raken leave towards WT. Which basically mean that they believe Rand will retaliate soon. They also know that such an attack would likely be composed mostly of Asha'man, so a pre-emptive strike on the BT to kill as many AM as possible makes sense now that they have traveling.



There is no way they don't. The location of BT is just too well known these days. It is not exactly something you can hide. They might not know the details of the place, but they surely know that its near Caemlyn. And even if they don't have the exact location, traveling&raken will deal with that.

Infact if they have been planning for this, it is not beyond reason that they might even have a rough map of what BT is inside. Elayne has been sending troops into BT repeatedly. All it would take is one soldier willing to take a Seanchan bribe and draw a rough map where the Asha'man sleep and presto.