The reason U.S. companies won't release the absolute most recent version of an Anime licensed game like Naruto is simply because fans have not been introduced to the playable characters in the latest game version.
Take Naruto: Clash of the Ninja for instance. Japan recently saw the fourth installment of this series released a couple of months back. However, the game contains about twenty characters that have not even shown up in the anime episodes that have aired in the U.S. thus far. So, while the U.S. publisher will financially benefit from selling sequels of the game, the games inherently follow the story development of the series.
Also, I can say with confidence that the licensed Naruto games are of surprisingly high quality. I have played nearly every single Naruto import across the PS2, Gamecube, and GBA and am surprised by the effective use of the liscense. The series single-handedly made me renounce my distrust of anime-based games. Well, at least for this particular series.
Oh, spudlyff8fan, did you draw that picture of Chouji yourself? Nice one.