Only things that's similar is that they're both desert planets. That's like saying why does New Mexico look so much like Arizona. The Jakku location isn't a leak. Disney has already given that info out officially.
In the Star Wars comic books that have been released this year, (which are considered cannon by Lucasfilm, meaning the story in the comics is tied into the actual movies) Han Solo's ex-wife is black. You can argue that Finn doesn't look biracial, but keep in mind Han also hangs out with a 7 ft walking dog that only communicates by barking, so Finn not being lightskinned enough isn't necessarily the most outlandish thing to digest in this series.