Kind of like saying that ChatGPT is people adding an AI player to the deterministic program of a chat

Except ChatGPT was written from scratch, so not at all like that

Tic-tac-toe is a classical example problem for neural networks 101, kind of a “hello world”

Doesn’t change that that isn’t how it was implemented to begin with. In your search results there are even people on Reddit asking how to add an AI player to their existing game. Seems like you gave me search results without even looking at them.