It'd be hilarious that meta chose to pay openai. If there was such a deal, would it come to light in any public/official filings?
No reason for it to. Software companies use products from other software companeis all the time.
meta already pays openai and anthropic for employee use despite having their own models available
Depends on the size of the deal. OpenAI would have to disclose it in their S-1 if it crossed the threshold of being material information for investors.