Love how they announce this after The Last Knight was the lowest grossing film in the franchise.
They have been working on this for a long time now. But timing is awful, they needed to have started this while TF and GI Joe movies were making some money, now it's kinda.... late.
And it's amazing how they haven't even attempted to tie GI Joe into the transformers movies, after creating like 3 different special government military units that interact with the bots in those movies, they could have easily written them into the background for easy spin off.
In the comics they pretty much used Tranformers as a means of creating MASK, government black ops stuff, using stolen Transformers tech to create their own special weapons which becomes the MASK vehicles and team. In one of the older cross over events they did, GI Joe was pretty much created just to help fight against Transformers.