From a quick google, it looks like if you are signed in with a Microsoft account, it will store that information in your account and then transfer that information to a new device that you log in to. So chances are, it resync'd for some reason and added them back in. The networks probably aren't actually available but show up as a list of known SSIDs.
You can try to remove them using the command: netsh wlan delete profile [wireless network name]
