I heard that in the future everyone would have similar skin colour because the intermix. Back then people more xenophobic but now it's as about open your mind
Those are just simulations some people do every year to say "look, we're reproducing ourselves with other ethnics and we'll keep doing so until we become identical" when reality says that except for those with money to move or get the partner moved to your country the structures will remain the same. Society is still stratified all around the world and endogamia is present, besides open minded people are more prone not to have offspring because they don't have the means or they don't want their children to live in an apocaliptic future. And regarding xenophobia... it's precisely now that it's rising due certain political parties.