It'd be interesting to see. African Americans and Latinos* make up about %28 of the US population, but are very under represented in startups. East Asians, South Asians, Arabs and Jews are over represented in tech based on over all population. What's more, most of the black programmers i've worked with at startups were born in Africa or the Caribbean.
I suspect that YC would be wise to try and recruit diversity, having different perspectives, backgrounds and world views among founders at the the dinners and other places, would probably make all the startups stronger.
Latinos or Hispanics are an ethnic group, not racial, there are white, black, native american, and asian latinos.