That wouldn't fit with the Seanchan worldview, nor Turak's personality I think (we've never seen them punish soldiers for the crimes/treason of their general, nor citizens for the resistance of their mayor/leader and such. It's hard to see why they would punish the whole "cult" that way, unless perhaps they gave them the chance to leave and swear the Oaths and warned them otherwise they'd share their leader's fate - and they all refuse to acknowledge the Seanchan were the armies of Luthair returned. Turak flew Luthair's banner (it hasn't even changed) and he was a Paendrag, and he arrived at Falme, where the Watchers were traditionally keeping their watch and so where they expected the Paendrags to show up again one day. I'd be curious to know exactly why the Watchers didn't fall on their knees weeping "they're back, they're back" and rather refused to acknowledge the Seanchan for what they were)

Jordan tried to show Turak as a honorable, fair man - not a cruel one.

Not that TGH itself provide any rationalization. Jordan was really intent on introducing the Seanchan as some sort of cruel monsters that would treat the heroes like animals given the chance. We were expected to take the manichean view and hate them (all the more with Suroth shown to be in league with the Shadow, and the mention of the Seanchan in the dark prophecy at the beginning of the book).

It's not before Egeanin's POV, and Suroth's that showed she was the one who was a mix of loyalty to the Shadow and loyalty to the Return, that he started to show not everything was black and white, or as it seemed, with the Seanchan. And it's not before Tuon's POV we got to really understand how the Seanchan leading class saw their laws and their justice, and that the Seanchan higher leaders really didn't see channelers as monsters, but more like we see mental patients, the type whose diseases can make them irrationally and unpredictably violent. Of course they don't have our modern sensibilities with mental patients, more those of the early industrial age, which to us are quite horrible (and that's where Jordan draw his inspiration from, by the way. The a'dam is most likely based off a device invented in England to tame violent subjects at asylums like Bedlam. All groups of channellers have an element or aspects taken from the history of madness/insanity (because Jordan draw his inspiration for channelling from schizophrenia), from the AOL that borrows from the Golden Age (when the insane are considered the wise, part of a kind of priestly class touched by the gods (and performing oracles and such), served by pure attendants, to the Wise Ones, borrowing elements from and playing a social role similar to the shamans - even their Dreamwalking is taken from there, to the story of the Sea Folk, who took to the Sea during the Breaking for protection and which mirror the "ships of fools" in medieval tradition where insane people were grouped and sent to sea, to the White Tower which echoes institutionalized asylums were the insane live in their own world, under the watchful eyes of their Warders, and rarely are left to go in the "real world" (I think part of the inspiration for TV is derived from the project of a specific mental patient in Bedlam during the Victorian Age, who had designed a fantastical utopian City, with a palace in the center that was an idealized Bedlam, the highest building in the world and all white and gold, from which he would rule as Emperor of the World). The AS advisors who can say anything they fancy to their rulers of course alludes to court fools, and the Kin and its farm are an allusion to the insane patients who were under the protection of the Quakers, as an alternative to sending them to the horrors of London's asylums. The Quakers believe the insane were happier in a life of work. They kept them busy with activies such as Knitting Circles, and farm work, for the women (the men were set to tend gardens). The Seanchan take after the more radical notions and methods of early psychiatry that considered the patients incurable, that they had to be kept under strict control at all times, and apart from society. Perhaps Jordan meant to inspire himself from real life too for the conclusion. It's largely women at first in the Victorian age who fought to humanize the treatment of mental patients. They took the side of the insane in the asylums. Incidentally, the device I believe inspired the a'dam (it's a metal collar, attached to a long pole. It kept the violent patient feet away from the warders/doctors) played a big part. The campaigns to force the British government to put an end to inhumane treatments and change the conditions in asylums in the Victorian age really started (or became huge) after articles and drawings of the new device in question appeared in denouncing articles in British newspapers. Perhaps the end to the a'dam won't come from the leaders but from the base (the obvious trigger at this point seems to be the fact experienced sul'dam are in fact pretty much handling the Power and not mad or dangerous for it - and no different from non-channellers being trusted to use damane properly and ethically, and Tuon herself is such a sul'dam. The whole justification for the a'dam is destroyed by this. Obviously it's strict rules for the use of the OP that are the solution, not devices to enslave channellers. If sul'dam can no longer be trusted as they too are channellers, the implications can be dire: either channellers can be freed as the sul'dam prove they can be normal and trusted to handle the Power and follow rules, or they must all be gentled/killed like the male channellers of old. I guess the view of channellers might change enough through TG for the people to finally refuse the worldview of the Seachan about them, refuse to stand up for it. Right now, they don't run to join those helping channellers (in part it's human nature, in part it's because the Seanchan for now have invaded the areas where AS are not liked, or even hated, and in part it's because AS have not done much to endear themselves for 2000 years, but the people don't like the treatment the Seanchan give them either. Things will have to change fast, because otherwise it doesn't take long to people to accept such things as what's normal and right (just look at the Seanchan masses).