Microsoft blocks Claude Fable 5 in internal GitHub Copilot over data retention

Category: Agentic coding
Status: confirmed
Sources: GitHub Changelog, Windows News
Summary: Claude Fable 5 became available in GitHub Copilot on 2026-06-09 for Enterprise and Business plans, with the policy disabled by default. Anthropic retains Fable 5 prompts and outputs for up to 30 days for safety classifier operation; flagged content is retained for up to two years. All other Claude models in Copilot continue under Zero Data Retention. On 2026-06-11 Microsoft issued an internal memo blocking its own employees from using Fable 5 within Copilot due to the 30-day retention policy.
Why it matters: Enterprises enabling Fable 5 in Copilot should review their data handling and DPA requirements before rollout; Microsoft's internal policy signals that the retention terms may conflict with standard enterprise data governance.