When Optimus Prime revived Sentinel, Sentinel went all nuts on Prime, but then Sentinel said " The War!, The War! " when Optimus said " The War was lost and Cybertron is now a burned out waste land " What does he means by the war was lost? Like the Decepticons won?
The Autobots fled the planet, the remaining Decepticons fled because there was nothing left on the planet to sustain any life. Most Autobots tend to be non-combatants so losing the War was inevitable.
While we're on the subject, in that same scene, Sentinel almost screwed himself. When he woke up, he didn't know what planet he was on and was confused. Two seconds later, he's talking about how the space bridge defies Earth's laws of physics. In the first movie, Optimus said Earth was an unknown planet in his opening monologue. That would mean he would already know about Earth for the impending plan. If someone thought about that for a sec, the plan would have been compromise. SAM: "Hey, Optimus, how does he know about our laws of...." OP: "SHUT UP, SAM!!! The robots are talking."
One has to note the Allspark's knowledge contained the collective history of the Transformer race to the present day. Which now lies within the Matrix of Leadership.
