OpenAI Names GPT-5.6 'Preferred Model' for Microsoft Copilot 365

Executive Briefing

• Signals partnership continuity after Bloomberg reported Microsoft expanding use of its own in-house MAI models to cut costs
• Covers Microsoft's core productivity suite including Word, Excel, PowerPoint, and Cowork
• Clarifies that 'preferred model' status doesn't negate reports of Microsoft increasing reliance on its own AI software
• Reflects ongoing ambiguity in the Microsoft-OpenAI relationship as both companies send mixed signals about their future