Via TFW2005, both The Hollywood Reporter and Deadline are reporting that Josh Cooley (co-wrote Toy Story 4) has been hired to direct a "big-scale Transformers theatrical prequel" said to focus on an origin story for Optimus Prime and Megatron, set on Cybertron. The script has been written by the writers of Ant-Man and the Wasp (Andrew Barrer & Gabriel Ferrari).
The Deadline article states that the work is being fastracked ahead of the Live Action series because it is easier to progress under social distancing. The other report states that it will act as a "prequel of sorts to the live-action Transformers movies".
Hopefully it takes the style of the Bumblebee scenes on Cybertron and builds off it.