Still, aside from The Last Knight and the Bumblebee movie, which are set to hit theaters in 2017 and 2018 respectively, little is known about future installments of franchise - especially the spinoffs. However, now we know that they won't be limited to the time period in which the movie universe has so far taken place. In fact, they could be prequels to the existing series.

During an interview with Screen Rant while on the set of Transformers: The Last Knight, producer Lorenzo di Bonaventura spoke about whether any of the spinoffs could take place elsewhere in the universe rather than stay Earth-based. He said:

Well, the animated movie is not Earth-based. That's a Cybertron-based movie. I think it's conceivable, but I think all of us involved, it’s sort of instinctive - to keep it relatable, you need an Earth relationship to it. It's not necessary, but I think we like it.

For moviegoers who aren't familiar with the Transformers mythology - whether from the animated series or the comics - but who are fans of the films, making future installments Earth-based will help keep the stories of Robots in Disguise relatable. Still, while long-time fans of the Transformers brand may be disappointed we won't see a movie that travels to Cybertron, Bonaventura indicated  films may be freer to move through time - particularly to the past, long before Sam Witwicky met Bumblebee. Bonaventura said:

You could do [different time periods]. For sure, you could do that. And we've examined - you could easily make an argument that in Roman times, you know what I mean? That seems like a good period.

Of course, the freedom to explore different time periods within the Transformers cinematic universe could and World War II, the Transformers franchise seems poised to explore a number of different time periods through its films.

That said, any prequel - or film with scenes set in the past - would still have to fit within the movie universe in of continuity, which does limit the time periods a spinoff could visit. Additionally, as viewers seemed to indicate with their responses to Transformers: Age of Extinction, a film following the Robots in Disguise must have a compelling story in addition to action spectacle. But, it seems the Transformers writer's room, which was filled with talent from both the film and television worlds, may help to boost Paramount's franchise - it certainly helped to win director Michael Bay back for Transformers: The Last Knight.

Next: Transformers: The Last Knight Set Report

Transformers 6 opens in U.S. theaters on June 28, 2019.