It's a bit more complicated than that. I worked in the bug reporting industry and 3DS either come in (at least) 3 flavours : North American, European and Japanese. Depending on the version of the console, it will try and change your game accordingly. If you have a North American console, it will change to French, English, Spanish maybe even Portuguese. But even if the game had Italian, you couldn't set it up so you could use Italian in game. You would have to have the European version for that.
I remember we had lots of problems while bug testing the French NA version of a certain game because the developer was uploading the French EU version on the NA cart and not the French NA version so it always was reverting to English...
But, yeah. If you had a NA 3DS and you changed your language to French, for example, your game would now be in French.