As someone who speaks more than one language fairly well: We can tell. AI translations are awful. Sure, they have gotten good enough for a casual "let's translate this restaurant menu" task, but they are not even remotely close to reaching human-like quality for nontrivial content.
Unfortunately I fear that it might not matter. There are going to be plenty of publishers who are perfectly happy to shovel AI-generated slop when it means saving a few bucks on translation, and the fact that AI translation exists is going to put serious pricing pressure on human translators - which means quality is inevitably going to suffer.
An interesting development I've been seeing is that a lot of creative communities treat AI-generated material like it is radioactive. Any use of AI will lead to authors or even entire publishers getting blacklisted by a significant part of the community - people simply aren't willing to consume it! When you are paying for human creativity, receiving AI-generated material feels like you have been scammed. I wouldn't be surprised to see a shift towards companies explicitly profiling themselves as anti-AI.
