Oh, I don't think the comic will assume that much. I mean, yea, you'll miss details, but after Dark Cybertron, they talked about the time Shockwave tried to collapse the universe and Megatron turned good. Combiner Wars, they talked about rampaging combiners and opening contact with the colony. Revolutions, dire wraith invaded and GI Joe got put in charge. Characters in IDW Transformers like to talk about stuff that happened before. I'll point to the City on Fire arc, where his initial RiD storyarc concluded with a defeated citywide uprising, Megatron and Devastator defeated, and Starscream in charge, and the Galvatron arc, which ended with ripping Galvatron's head off in Jupiter and he annexed Earth. Barber has done some pretty nice conclusions in there, and some of the dialog strongly indicates to me he's got a game in mind with our Optimus.