OpenAI Names GPT 5.6 Microsoft Copilot's Preferred Model

OpenAI announced GPT 5.6 as the preferred model powering Microsoft 365 Copilot, covering apps like Word, Excel, and PowerPoint. The move appears aimed at countering reports of a growing rift between the two companies after Bloomberg revealed Microsoft was expanding use of its own in-house MAI models to cut costs. However, the preferred model label lacks clear definition, and OpenAI's announcement does not contradict earlier reporting. Microsoft was never said to be fully replacing OpenAI, only supplementing it with its own software to reduce expenses.