So these types of posters have been seen before. /u/dwarvenhobble has a great post over on reddit KIA listing some of the background.  Personally, I don't think there is any concrete evidence yet to link UnsavoryAgents to this. Besides GG message doesn't seem consistent with the type of work they do. However, the style is easy to mimic and has been done before. I also am hesitant to jump the gun and outright say this is something done to hurt GG. Misguided or pushing their own agenda maybe.