Personally, I think it would be better if students had a 'right' to attend a dual language school in their language if they speak a language other than English at home. I realize that it would require a lot of language evaluation and probably wouldn't fit the district's idea of equal access, but I think if 'fairness' is the criterion we are considering, it isn't very fair to deprive children of the right to study in English and in their native language. All research on the topic has concluded that, when done right, education in one's native language has a positive effect on school outcomes. By letting boundary, at-risk, random, or whatever students in before bilingual students who have the most to gain and lose seems unfair to me.
Now overlay with the percentage of Black students in the DCPS neighborhood schools, and that will tell you everything you need to know about the supply of dual language schools.