They did that, that's how Reid Hoffman got early access to write his book, that's how Microsoft got access to start working on Bing/ChatGPT4 for a cool $10 billion and that's how countless of other got early access. Got the money, got the marketing and got the synchronized deployment of multiple use cases by a selected crew of companies and they get to say the corpspeak of 'we care, we didn't release on August!'. This is taken from the Apple iOS SDK book, you make the API changes and release privately to have the announcement and a parade of implementations by third party to prove that it is viable.