As for the article itself, I'm not sold. The analysis was about narrowing down to find the most recent regional split in our genetics, with the assumption that language formed before humans split across regions. That would work if we assumed the capability to develop language rested largely on genetics. If a lot of animals could develop a language, then the explosion of human language could come from imitation when one regional group without a language meets another with a language.
>"Human language is qualitatively different because there are two things, words and syntax, working together to create this very complex system," Miyagawa says. "No other animal has a parallel structure in their communication system. And that gives us the ability to generate very sophisticated thoughts and to communicate them to others."
I have seen a lot of ideas about human mental exceptionalism fall apart. It wouldn't surprise me to find out in a few years that dolphins developed syntax.