The Lando message is good! I can’t even tell it was a phone recording. It seems like you used a radio tuning effect on the audio, but it’s not a very Star Warsy sound, if that makes sense.
I know it isn’t included with a hologram, but I wonder if you could a sound effect more like this.
I know originally the suggestion was that the audio would be included with the shot of the Imperial shuttle going through hyperspace, but I think it would also be fitting to show a shot of the Falcon in hyperspace as if it is transmitting the message as it flies around the galaxy, and/or maybe back-to-back establishing shots of random planets, to imply these are some of the places that are receiving the message. It could be a good way to set up planets like Coruscant, Bespin and Naboo revolting at the end of the movie, because they got the message from Lando earlier.
EDIT: I also like the more demonic sound of the Emperor clip. I hesitate to say it is a little too demonic, but sometimes you can be too subtle. But it definitely does sound closer to how he sounds in Revenge of the Sith.