OpenAI CEO Sam Altman and Microsoft CTO Kevin Scott at the Microsoft Build developer conference in Seattle earlier this year. (GeekWire File Photo / Todd Bishop) Microsoft disclosed the size of its OpenAI investment for the first time, acknowledging in its quarterly regulatory filing Wednesday afternoon that it has made “total funding commitments of $13 billion” to the ChatGPT maker. That footnote in the company’s financial statements confirmed widespread reports about the magnitude of its inves...