OpenAI says GPT 5.6 is the ‘preferred model’ for Microsoft Copilot 365 amid breakup chatter

OpenAI has announced that its new GPT 5.6 model will become the "preferred model" for Microsoft's 365 Copilot, a move that appears aimed at quelling speculation about a rift between the two companies. This announcement comes after a Bloomberg report earlier this week indicated that Microsoft was increasingly replacing OpenAI's software with its own in-house models, known as MAI, in apps like Word and Excel to cut costs, raising questions about the future of their partnership. During the launch of GPT 5.6 on Thursday, OpenAI stated that the model would support Microsoft users across its productivity suite, including Word, Excel, PowerPoint, and Cowork. In a blog post, OpenAI emphasized its shared commitment with Microsoft to bring advanced AI to more individuals and organizations. However, the exact meaning of "preferred model" remains unclear, and the disclosure does not appear to contradict the earlier reporting that Microsoft is relying more on its own software to reduce expenses.