> And independent of whether Microsoft makes money or not in their OpenAI endeavor, it kills the story: they were betting the whole growth story on AI, and if that doesn’t work out, then what’s left to justify a high stock price?

Microsoft's stock price today is the same as it was in late 2021 before anyone cared about AI. What would happen? Nothing. I don't think it's a significant revenue driver today. Microsoft, like everyone else, is speculating that AI will drive profits in the future. If it all fell apart there will certainly be losers but I don't see why it would bring down Microsoft.