Microsoft begins swapping OpenAI and Anthropic out of Excel and Outlook for its own MAI models

Summary

Microsoft has started replacing OpenAI and Anthropic models with its own internally built MAI models inside widely used Office applications, beginning with Excel and Outlook. Per reporting (originally Bloomberg, corroborated across trade outlets), tens of thousands of AI prompts in the spreadsheet and email apps are now completed each week by MAI models rather than the third-party frontier models the features previously leaned on. Microsoft frames this as a continuation of its multi-model strate