A little over a year ago, the MIT Technology Review ran a piece about how outputting AI content to non-English Wikipedia is rapidly corrupting the primary training data for uncommon languages because of exactly this process: https://www.technologyreview.com/2025/09/25/1124005/ai-wikip...
A human did this first with Scots Wikipedia by rewriting English articles in Scottish eye dialect of English and passing it off as Scots.
It's funny to think that pre-LLM archives are the new low-background steel.