If knowledge of the SW movies is in play... things don't look very good for us if the Imperials reach us first. After the inevitable defeat/surrender, people are going to blab about the Star Wars movies. Once Palpatine hears about it he would extract whatever info he can for personal gain, which would almost certainly lead to the destruction of the Alliance. He'd probably kill Luke and Leia to keep Vader obedient (or kill them all just to be on the safe side). Then he'd probably Base Delta Zero Earth to make sure the information doesn't leak out. We know wayyyyyy to much information about him and he plans, he's not going to risk letting anyone on Earth stay alive.It's worse than that. There are too many people on earth who know the same things you do. Hiding the existence of the SW movies from the Empire would be impossible. Best case is that Earth is put under quarantine to keep that information contained. But a quarantine would require enough people who Palpatine trusts to keep the secret to enforce it. I doubt he can spare enough people he trusts to stay quiet if they know, so it would be people he trusts to ignore all communication attempts from the planet they are blockading.
The biggest threat of something slipping through the blockade would not be someone from Earth breaking out. It would be someone from outside slipping in and smuggling a copy of the movies out.
If the Rebellion happens to get into contact with Earth first, things might get interesting. How do you think they'd react to the info from the movies? Would they do anything to protect us, if they are even able to do so? Or would they also Base Delta Zero us to make sure that the Empire doesn't find out that it eventually falls? With the entire Galaxy at stake, it'd certainly be tempting for them to do so.