It was unexpected but not too weird, Mat's various deaths have spawned a lot of theories - Edit 1
Before modification by Isaac at 12/01/2013 01:01:35 AM
Personally I found the entire Horn subplot with Faile to be unnecessary, ditto the stolen seals. Not bad exactly but in an already absurdly long final book-turned-trilogy I think the loss could have just been accomplished by having Egwene have both at the WT command post and having them fall into enemy hands or just get lost when Demandred showed up with the whole damn Sharan army. A rescue or recovery operation then would have fit a lot better and felt less shoe-horned. Hell it would have made Gawyn's death more logical and less forced if Demandred had them and Gawyn felt the Blood Knife rings might have granted him the chance to rescue them.