OpenAI used the launch of GPT-5.6 to underline that its models remain central to Microsoft 365 Copilot. TechCrunch reported that OpenAI described GPT-5.6 as the preferred model powering Microsoft's productivity assistant across Word, Excel, PowerPoint, and Cowork.

The statement matters because it follows reporting that Microsoft has been leaning more heavily on its own MAI models inside Office apps as part of a broader effort to control AI infrastructure costs. That shift raised questions about whether Microsoft and OpenAI were moving farther apart after years of unusually close technical and commercial alignment.

OpenAI's wording does not fully answer that question. "Preferred model" confirms continued use of OpenAI systems in Microsoft 365 Copilot, but it does not say that Microsoft will stop using in-house models or that every Copilot feature will route through GPT-5.6. The conservative read is that Microsoft is keeping OpenAI at the center of flagship Copilot experiences while also diversifying the model stack behind them.

TechCrunch separately reported that GPT-5.6 is part of a new OpenAI model family promising improvements across several areas, including cybersecurity. The Copilot disclosure gives that launch an enterprise distribution angle: if Microsoft keeps GPT-5.6 as the default or leading option for core Office workflows, the model could reach business users first through familiar productivity software rather than only through ChatGPT or the OpenAI API.