As stated, since regionfour doesn't change your console's actual region, and thus the language your console is in, then certain games (the ones the OP mentioned) will only display in the system's language, regardless of region unlocking. The only way around this for these games, from the information I've gathered in the short while I've joined this scene, is to region change your console. My only guesses as to why this happens in this way comes out to 2 scenarios: either at one point, Nintendo toyed with the idea of removing the 3ds region lock, and so making these games' language change based on system language made sense, or it was a way for them to further lock down the regions, for such a case as the region unlocking that is currently going on. Purely conjecture, but either scenario makes sense to me, and personally, my money is on the latter scenario, given the specific titles that same to suffer from this.