If you are generating tests with an LLM, it's not deterministic.
Also, have you actually read anything an LLM wrote that's longer than a hundered words? It's usually immediately obvious. In the open source world things I keep seeing are exchanges like this one. And Niri is a fairly good case with it's maintainer actually reading the PRs and catching all the bullshit that an LLM spits out. Very often nowadays people will also do reviews with an LLM and this sort of stuff will just accumulate in the codebase with nobody to reject it.
But even if it was as useful as big tech paints it to be, I'll always be against using it based purely on morals. There is an enormous number of issues in that regard, most importatnly LLMs literally kill people both directly and indirectly. Condoning the adoption of this technology is either being ignorant or misanthropic.