Translation, in and of itself, is viewed as a creative work. A translated work has two copyrights: the original, and the translation, with permission needed from all rightsholders to redistribute. A new translation of a public domain work (Emily Wilson’s The Odyssey) has one copyright holder, the translator. An existing work (the English translation of The Three Body Problem) has at least two: the original author and the translator.

However! Since AI work is noncopyrightable, the AI’s effort in translation is simply ignored. Claude’s The Odyssey would have zero rightsholders, and remain public domain. ChatGPT’s translation of The Three Body Problem would still be under Liu Cixin’s copyright.