Now it's a classic, you need an expert in order to check the work of the machine, because the "customer" is by definition not able to do it.
Aside from highly technical domain, in purely literary works, I think that the translator is a co-author - maybe IP laws acknowledges that already? I remember the translation of E.A. Poe by C. Baudelaire for instance; I think you could feel Baudelaire's style because it is a lot "warmer" than Poe's. I've also read a translation of a Japanese novel and I was quite disappointed with it. I don't know Japanese but I have read/watched quite a few mangas/animes, so I could sense the speech patterns behind the translations and sometimes thought they could have made better choices.
In any case, one will still need a translator who is good at "prompt engineering" to get a quality translation. I don't know. Maybe translators can add this skill to their CV, so they can propose quick-and-dirty/cheap translations, or no-AI high quality translations.
Some suggest "no-AI" labels on cultural products already - I think if it becomes a reality it will probably act as "quality signaling", because it is becoming more difficult every year to tell the difference between AI and human productions. It won't matter if what you read was written by an AI or a human (if it quacks and looks like a duck...), but what the customer will probably want is to avoid poorly-prompted machine translation.