I would have thought the Wizardry games would be more popular in the U.S. than in Japan so it seems a little strange that it was never ported or that it was even released in Japan first (or at all). I guess it comes down the popularity difference of the Saturn between here and there and its short life here.
I'm not sure what other code mods are needed to do a translation (I'm sure there could potentially be issues with memory allocation or the size of the text boxes or whatever depending on how it was done). However, it seems like the translation itself would be a lot easier these days since a machine could do it and it would already probably be close enough.
RE: Wizardry VI on Sega Saturn Translated to English by Talented Fan