According to Paramount: The Last Knight shatters the core myths of the Transformers franchise, and redefines what it means to be a hero. Humans and Transformers are at war, Optimus Prime is gone.
Director Michael Bay published a letter to fans:
We brought in Transformers historians from Hasbro to educate them on where Transformers has been – so that they could figure out where it can go.
I can safely say that there’s never been a Transformers film with the huge visual scope and expansive mythology as this movie, The Last Knight.