Well they said that the toy is inspired by the theme of Age of Extinction and also styled. So idk, it could be the actual design and because it's new they went back to basics like the 2007 Optimus, or it could be that it's just a spin-off toy design.
Yeah, I'm mostly going off of the design from the new toy while throwing in some bits and pieces from the past Movie!Optimus designs. When they finally show us the CG render I can do even MORE pictures that are actually accurate. For all we know the Toy is just a spin off design and not even the actual thing (like the Ultimate Optimus Prime toy)