Comment by retsibsi
In the end the analogy doesn't really work, because 'eternal September' referred to what used to be a regular, temporary thing (an influx of noobs disrupting the online culture, before eventually leaving or assimilating) becoming the new normal. 'Eternal {month associated with ChatGPT}' doesn't fit because LLM-generated content was never a periodic phenomenon.
AI R&D certainly was periodic. Good thing we put a stop to that!