My "guess" is that it means MSFT has access to sell products based off the research OpenAI does to MSFT's customers. Having early access to advanced research means MSFT could easily make this money back by selling better AI tools to their customers.
Also a great time to point out that while "Microsoft is not a charity foundation" it does offer a ton of free Azure to charities. https://www.microsoft.com/en-us/nonprofits/azure This has been an awesome thing to use when helping small non-profits with little money to spend on "administrative costs".