I'm watching the season finale again, and if the writers do something crazy and awesome, they could keep Spoiler Prime dead and allow Smokescreen to become Rodimus Prime. I know that seems strange at first, but think about it. Orion Pax became Optimus Prime. Other than the O and the P, the name changes drastically, so it's hypothetical that this could be a really cool turning point where they can designate a new leader. Of course, it's highly improbable, but speculate away.