Not so sure of this, watcherofthesouth.
Harry's descendent ruler, moon, in the 5th almost exactly trines sun in 8th, and he married a Leo. A Romantic (5th) and very sexual (8th) relationship.
His sun in square to Neptune in the 12th, as well as moon inconjunct Neptune shows all the gossip surrounding his wife, and so many "unknown" factors about her.
Interesting, when she said "I do", thereby legalising the marriage, Neptune was exactly conjunct the descendent, fulfilling the aspects in Harry's chart.
Harry's Venus, symbol of the women in his life, is conjunct the cusp of the 9th house of foreigners. Before Meghan, he had a long term relationship with a woman from South Africa.
The wide opposition of moon and Saturn I think refers to the fact that there is a conflict in his marriage relationship between who he is and who his marriage partner is.
Saturn in this case could also refer to the fact that he would marry an older woman. The sun and Neptune seem to give a more accurate description of her.
In his chart, I don't see an aspect that would clearly indicate he would choose someone of another race (even if she is mixed), rather than just another culture.