Thats correct. If you want to feel safe I would do this (What I am currently doing, some people may say its over the top but I prefer to be safe then sorry). When you have WAD's installed, delete your connection info from the wii settings (So it has 0 way of going online). When you want to go online, use the wad uninstaller and uninstall all wads, put your info back in and go online.

I suggest if you have ever used VC or WiiWare WADS that you never visit the Shop again, just my suggestions to make things 'safer', however there is never any sure fire way to be safe as we dont know what Ninty will do in the future.