G.I. Joe and Transformers are Related
But not in the way you think. Yes, the same toy companies produce both, and yes, the two universes have crossed over in a handful of comic books and animation cameos. But rather than printed paper, this family tree branches via plastic. The Robots in Disguise's lineage goes all the way back to America's Moveable Fighting Man.
In 1964, Hasbro released the original 12-inch G.I. Joe action figures. Within a few years, Hasbro had licensed the figure to toy companies around the world for sale in markets like England and Brazil. In Japan in 1972, Takara released a toy called Henshin Cyborg, a clear-plastic version of the Joe body with mechanical innards. Two years later, Takara shrunk the figures and renamed them Microman. Two years after that, Micro Change introduced transforming robots to the mix, including a Lamborghini that hopped into Takara's Diaclone line in 1980.
When Hasbro saw Takara's attempts to release Dialone as Diakron in the US, it partnered with the Japanese toymaker to release many of those Microman and Diaclone cars, planes, cassette players and Walther P-38 pistols as the 1984 and 1985 Autobots and Decepticons. So in a very real way, G.I. Joe helped create the Transformers. No Creation Matrix needed here.