Good question. First of all, people control the genes they are looking for. Algorithms just find people according to given parameters, they are not racist.

Second, there’s nothing racist about preferring people in your own ethnic group. Most people find their own race most attractive for a partner, and there’s reason to believe that will still be the case in a post-racism world. Yes there will be mixed couples, but people who want a mate from their own race aren’t racist.