Microsoft restricts Claude Fable for employees over data retention concerns

Anthropic released Claude Fable, its first Mythos-class AI model, yesterday and it's already causing concerns inside Microsoft. Sources tell me that Microsoft is limiting the use of Claude Fable 5 for employees because of Anthropic's new data retention requirements.

While Microsoft quickly rolled out Claude Fable 5 to its GitHub Copilot and Foundry customers, I'm told the model isn't available in the model picker that Microsoft employees use for internal versions of GitHub Copilot.