Ok, so there were a bunch of fake signatures. The post you linked also says "Edit: Just to clarify, the open letter is real and most of the signatures are real (Elon Musk, Gary Marcus, Emad (stablediffusion creator) all did sign it and fully support to ban research on GPT models stronger than GPT4 for at least 6 months".
So my point stands.
Andynonomous t1_jegxl0f wrote
Reply to Open letter calling for Pause on Giant AI experiments such as GPT4 included lots of fake signatures by Neurogence
Ok, so there were a bunch of fake signatures. The post you linked also says "Edit: Just to clarify, the open letter is real and most of the signatures are real (Elon Musk, Gary Marcus, Emad (stablediffusion creator) all did sign it and fully support to ban research on GPT models stronger than GPT4 for at least 6 months". So my point stands.