From a Catholic perspective, substituting "black" for "gay" falsifies the document, and how it sounds to modern ears is irrelevant.

The Church is silent on the source of “sexual orientation”, whatever that currently means in today’s jargon, except to note that the natural order is attraction between a male and a female.

Science has literally nothing to do with that.

Nor is there any comparison between racial bias and the Church’s teaching on same sex attraction. The comparison is a political one designed to equate two quite different things.

Since the Church’s teaching is based on the Natural Law, not St. Paul’s letter to anyone, it is not going to be changing. 

http://www.vatican.va/archive/ccc_css/archive/catechism/p3s1c3a1.htm

1979 The natural law is immutable, permanent throughout history. The rules that express it remain substantially valid. It is a necessary foundation for the erection of moral rules and civil law.