Transformers: Rise of the Beasts creates the perfect setup for Transformers 8 to repeat Unicron's 37-year-old storyline and introduce the Decepticons. The Decepticons remained the primary antagonists in Michael Bay's Transformers movies. However, in the live-action Transformers reboot films, Bumblebee and Transformers: Rise of the Beasts, the Decepticons have barely had any screen presence, let alone face-offs with the Autobots. Fortunately, Transformers: Rise of the Beats has not only paved the way for their introduction in Transformers 8 but has also set the stage for Unicron's return.

https://screenrant.com/transformers-8-unicron-1986-story-setup-decepticons/