I didn't want to post that myself, as it's a pretty big potential spoiler, but seeing as you have I'll talk about it. I think you're right. It definitely looks like Starscream. I hope it's not him, but it really looks like him.
I honestly can't tel,l but since this is the final movie in the series and this scene probably happens near the end big climatic battle I would not be surprised if Starscream dies.
"How I loathe heroes! Always getting in the way and acting so... so... heroic!"