As a CS professor, I can't tell you how many times we've lost students with great potential in CS because they had no prior experience but were comparing themselves to inferior students with a year or two of programming experience in high school. If you get the students who have prior experience into a "fast track" class (e.g. that compresses the first year into a single term) then both the "experienced" and "naive" students can actually learn at their own pace. Fortunately, I teach at a small college, and so most times we can identify those students and get them into a better class. And I'm actually in favor of having students with a lot of experience start by skipping a class or two. The sooner students are surrounded by their "peers" in ability/experience, the faster and more reliably they're going to engage.
But to be clear: the issue isn't that people should be actively sorting the students so that only female and non-white students are in the CS1 class. That's a horrible idea, racist, sexist, and all the other "ists" you can come up with. It is likely that the "normal" track will have more non-white and female students in it because that's what the high school demographics say: non-white/non-Asian/female students are less likely to have prior experience. But it's also true that there will be more students from rural schools in the "normal" track, because rural schools are less likely to have computer programming courses.