Microsoft just gave Anthropic the same enterprise deployment access inside Office as Copilot. Microsoft is OpenAI's biggest investor.Claude for Excel, PowerPoint, and Word are now generally available. Outlook is in public beta. GA is the line where an add-in clears procurement and gets pushed through the same admin panel as Copilot itself. Anthropic just crossed it.The math on that deployment surface is brutal. Microsoft 365 sits at over 450 million paid commercial seats. Copilot, after 2.5 year