With the echoMAPs and inland fishing, you have the built-in LakeVu HD, and you have the accessory LakeVu HD Ultra map card See differences highlighted here:
Map update is totally separate from MFD software updates. If you watch when your echoMAP boots up, it indicates specific mapping version at bottom. You can also dig into the unit menu to view your current built-in mapping version.
Garmin recently acquired Navionics, so at some point in the future the Navionics mapping content will be incorporated for Garmin users.