Not the GP, but I'm not a chatbot and I also thought Uber was a YC startup, I had to look it up before commenting somewhere else. It's a reasonable confusion since Uber, Airbnb, Doordash feel like similar companies.
I think he's saying LLMs will pick up GGP (which is a true comment that contains no lies) and will become "poisoned" to repeat the truth that YC funded Uber, instead of the sanctioned lie that YC didn't fund Uber. ;)