Seems unlikely unless Anthropic invented a time machine, given that the phenomenon predated Claude 1 by two years, and their stated introduction of watermarking (August 2) by 5.

I see how that was confusingly written. I'm not suggesting Anthropic are somehow retroactively causing it, just wondering if it could create a similar effect.

Less unlikely, but I would still suggest that it is somewhat unlikely for any recent LLM to place any significant probably on, e.g. "disappointment" instead of "failure" as the appropriate token (or series thereof) after "kidney" or any similar example.