Microsoft has blocked its own employees from using Anthropic's newly launched Claude Fable 5 inside GitHub Copilot, citing unresolved concerns over a 30-day data retention policy tied to the Mythos-class model. The Verge melaporkan tim hukum Microsoft masih meninjau perubahan tersebut, meskipun pelanggan Copilot dan Foundry yang membayar sudah memiliki akses. Model Claude lainnya tetap tersedia secara internal berdasarkan aturan Nol Retensi Data. Anthropic belum menawarkan solusi.