Apple doesn't have approval rights when you distribute Mac software outside their App Store.
Signing just requires that you have a developer certificate and pass a virus scan.
I was actually surprised not to at least see "your app must agree to abide by some basic terms of service" on the list of requirements. It seems like a mostly automatic system.
At the same time, I would also be surprised if Apple were explicitly alerted by Hollywood lawyers of the fact that an app like Popcorn Time was endorsed in any way by them, and they didn't proceed to revoke the signature.