GPT-5.6 is now the preferred model in Microsoft 365 Copilot
Executive Take
Enterprises running Microsoft 365 Copilot get a model upgrade with no procurement action required, but leaders should audit whether Copilot outputs used for compliance, finance, or client-facing work now behave differently before relying on them unchanged.
Executive Summary
Microsoft 365 Copilot has adopted GPT-5.6 as its preferred underlying model, according to OpenAI, with the update applied across Word, Excel, PowerPoint, Chat, and the Cowork feature, intended to improve output quality and speed for Copilot users.
Why It Matters
Technology and AI leaders should care because this silently changes the reasoning engine behind a productivity tool many employees already use daily, affecting output consistency, accuracy, and governance without any visible rollout announcement to end users.
Bizquad Perspective
The real story isn't the model swap itself but that enterprises now inherit frontier-model behavior changes on Microsoft's and OpenAI's release schedule, not their own—governance teams should treat this as a recurring, not one-time, risk.