The term has been around in this context since at least 2018[1], and indeed I have chat logs from 2019 talking about how mtl [machine translation] hallucinates, so no, this has been what people have been calling it for a while now. Perhaps what you're seeing is just rising awareness that this is a weakness of current-gen ML models, which is great, now even monoglots get to feel my pain :V

[1]: https://www.wired.com/story/ai-has-a-hallucination-problem-t...