Bloomberg recently reported that Microsoft was swapping some OpenAI software for its own in-house MAI models in Word and Excel to save cash, sparking breakup rumors between the two frenemies. But OpenAI just fired back with a commitment: its new GPT 5.6 will be the “preferred model” powering Microsoft 365 Copilot across Word, Excel, PowerPoint, and Cowork. The language is vague—it doesn’t nix those cost-cutting moves—but the message is clear: OpenAI isn’t getting booted from the house. This drama highlights a delicate dance: Microsoft wants cheaper AI, but still relies on OpenAI’s top-tier tech. Why it matters: This power shift shows even tight tech partnerships get messy when money talks, but branding still matters more than back-end changes for keeping users loyal.