Yeah. Except that he specifically mentioned Wiktionary as the source, and even if UD was the dictionary in question: why do you think they decided to name it "Urban Dictionary"? I'm sure that it was just completely coincidental that they picked 'urban' for a site built around defining slang terms.
It doesn't 'necessarily' imply that, but it is a widely-used euphemism for inner city hip-hop culture. Acting like it's not, that the term arises from the name of the slang dictionary (and not the other way around), is just wrong.
