I didn't completely disagree with you, Icehorse, by the way. Your earlier assumption is in place, but I don't think it is a significant factor unless those attacks were planned for by organized factions with motives prior to the attacks (maybe I S I S implanted some of their own with the refugees?).
Even I, a very well educated (I'm not bragging here) Muslim Saudi national living all my life in the center of the Muslim world Makkah, never been taught about the subject topic the assumption is based on, not to mention that enslavement in Islam takes place under strict specific cases. Just taking a non Muslim woman claiming her a slave does not work.
As for the education and having culture and religion intertwine, that's a correct thought. However, when this specific relationship forms, it forms based on what the culture needs to live, based on the religion it wants to adopt. Religious teachings related to, for example, marriage and food consumption, I believe are used and taken as significant factors. If we take slavery, we know that it is now not allowed under civil international treaties by the officials (Islam considers that seriously and there are verses in the Quran for it) so it became a disconnected religious act to be even taught of. Like I said, even I did not get any of that in my culture which is considered one of the most strict Islamic.