Yes, social structure does play a complex role in "Trojan Women." Euripides was, considered by some, an ancient world feminist. Read "Medea" and you'll understand why.
For "Trojan Women" the women of Troy are taken as slaves. Look at the type of slavery imposed on the noble women of Troy. Noble women were but into slavery, yes, but typically in the homes of noble conquerors. They were treated with some level of respect in comparison with the lower classes. Also, consider that women were valued for their beauty above all else. Women had absolutely no rights in the ancient world and were awarded little freedom and treated as property to an extreme degree. It was considered a harsh insult to conquered lands to enslave its women, especially to enslave the noble women of a land.