However, Michael Bay himself just confirmed that Generation 1 Onslaught will be in the 5th Transformers film via his Twitter account.
It seems as though Michael Bay is trying some different with Transformers: The Last Knight by blending characters (both human and robot) from his original trilogy and the 4th film, Age of Extinction, while throwing in a much-needed dash of nostalgia with Onslaught.
Although Onslaught is already a well-established in the animated Transformers franchise, we have yet to see him in any of Michael Bay’s films.
Transformers: The Last Knight is currently filming; however, little is known about the film itself.