The reason it does that is because there are multiple launchers installed in the device, and the device likes to know which launcher you prefer to be the default launcher. It doesn't matter what kind of launcher it is or what circumstance it's under(backup, update, installing).When you do get the update I would bet that the phone is going to ask if you want touch wiz or nova launcher as your default launcher. Any time I've taken update that's what happens. Hopefully you'll be getting that update sooner than later ☺
Sent from my rooted Vzw LG G3 on a couch in Portland Oregon