Well, the title says it. When you draw your weapon out of combat, your companion draws it as well. When you sheathe it, so does your companion. This would look really cool, especially for taking screenshots. If you look at the movies, you'll see that most of the times people draw their lightsabers at the same time, for example,
https://youtu.be/eYT3ctPuVRw?t=1m2s
https://youtu.be/pUbXyd-fK8Q?t=1m19s
https://youtu.be/xmR1ee223zQ?t=5m55s
https://youtu.be/YBLcxXR1PMw?t=16s
please make this happen dear devs, thanks in advance