I think that the difference is that in the bangles case, they are integral to the faith, whereas a chastity ring was not.
There were also a lot of interesting conflict-of-interest questions regarding the parents of the chastity-ring girl...
So no, nothing to do with minorities.
Ian
“Mankind have a great aversion to intellectual labor; but even supposing knowledge to be easily attainable, more people would be content to be ignorant than would take even a little trouble to acquire it”
- Samuel Johnson