No. And that's not a bug.
Riivolution requires an updated IOS37; if you're on System Menu 4.2 you should be good. If it's not installed or the proper version, it will be installed the first time Riivolution is run.
Alternatively, you can also use NUSD or DOP-IOS to install it - with all patches disabled.
I probably haven't played it, but yes, it should; try it. If it doesn't work, report it - some games known to reload IOS will require specific patches to work.
Games that have specifically been tested include Fatal Frame 4, Super Smash Bros. Brawl, New Super Mario Bros. Wii, Rock Band, among others.
It will install a Riivolution channel onto your System Menu for easy access. This can always be uninstalled.
Normally, Riivolution just supports direct memory patches. However, Riivolution supports a patching method that can be used with the Gecko OS code handler.
Read more about that here.
As a user, you need to either download patch packages made by someone else or make your own.