May be some truth in this article, but I don't trust journalist who list "God" as "G-d. It's Tony Snow, for goodness sakes. Who else are you going to trust!? As for the G-d thing, some people do that out of respect for God or something like that.
Tony Snow was quoting Karenga's "pledge", and the G-d may be verbatim from the Official Kwanzaa website.