Could you link me to that? I'm not trying to put you on the spot or anything. I've just seen multiple references to this supposed cosign but haven't come across it myself. It could potentially be one of the more interesting elements to this whole shenanigan.
The article was on OkayPlayer, but I can't find it there anymore. But I did find an article on OKP mentioning a supposed project that Droog and Nas are working on (to be released on Mass Appeal Records).