This is a pretty minor theory, but it may provide a small clue to the whereabouts of Myrelle and companies party to the black tower. In TSR, Min had a viewing of 'an apple-cheeked Accepted' where "bars floated in front of her face like a cage."

The accepted in this viewing was never named, and until now, I don't think we have seen a specific instance of an accepted being imprisoned. Theodrin has been described as having a round apple-cheeked face at least once. Theodrin was also an Accepted at the time of Min's viewing, and there weren't tons of Accepted walking around in the WT then.

I believe Min's viewing may have had to do with Theodrin being imprisoned in the future. This would dovetail with her current expedition to the BT and the fact that she has not yet returned.

As Deadsy has already pointed out, Min also had a viewing about Faolain: "A nasty woman - if there was any fairness in life, you'd think she'd have an unpleasant future ahead of her" From this perspective, Myrelle, Nisao, Faolain, and Theodrin may not have suffered irreparable harm yet.

Unless her good thing was being raised to Aes Sedai, then Faolain at least will most likely be rescued from her current debacle.

*edit-- I had to revise this theory because I got Theodrin and Faolain confused. But I have it resolved now, and I double-checked the text to make sure it was Theodrin that was described as being apple-cheeked.*