Microsoft is bringing Business Central agents to GPT-5.3-chat: what is changing for admins, consultants and developers?

Microsoft announced that between May and June 2026, Dynamics 365 Business Central agents will start moving to GPT-5.3-chat as the default model starting with version 28. This isn’t just a simple switch, though-it also brings model management capabilities into the agent design experience, plus new SDK methods to control model selection from AL. So it’s definitely more than just a “new engine” under the hood.