The hosting is not the issue. Github would have different security requirements for code hosted in a private repo for a paying org than OpenAI would for free us

The hosting is not the issue. Github would have different security requirements for code hosted in a private repo for a paying org than OpenAI would for free users sending prompts to an LLM. It can and should be assumed anything you type into ChatGPT is being logged to be potentially read by a human.