Microsoft 365 Copilot: 8 New Features to Test

Introduction

Microsoft 365 Copilot continues to accumulate updates at a steady pace. New language models, office automation agents accessible to all, generalization of Copilot notebooks: these developments are concretely changing how users interact with Copilot Chat on microsoft365.com. Here are eight new features to know about, with their licensing requirements and current limitations.

New Models: GPT-5.6, GPT-5.5 and Claude Opus

In Copilot Chat, the model selector ("Auto" dropdown menu) now offers multiple options beyond automatic selection:

• Claude Sonnet (Anthropic): lightweight model, optimized for response speed.
• Claude Opus (Anthropic): most capable model in the Anthropic range available in Copilot.
• GPT-5.6 (OpenAI): available in "think deeper" mode or quick response.
• GPT-5.5 (OpenAI): available in quick response.

The "Auto" mode lets Copilot Chat choose the model best suited to the request. For tasks requiring complex reasoning (analysis of long documents, multi-source synthesis), forcing GPT-5.6 in "think deeper" mode or Claude Opus generally gives better results than automatic selection, at the cost of a longer response time.

Word, Excel and PowerPoint Agents Accessible to All in Copilot Chat

The specialized Word, Excel and PowerPoint agents, invoked via @mention (@Word, @Excel, @PowerPoint), are now available to all Copilot Chat users, with no additional add-on required.

Operation is identical for all three agents:

1. The user mentions the agent and describes the desired document, possibly attaching a source file (URL, spreadsheet, existing document).
2. The agent asks one or more clarification questions: document objective, target audience, length, visual theme.
3. The document is generated directly in the chat pane, then can be opened in the web or desktop version of the relevant application via the "Open in Word/PowerPoint" button.

For the Word agent, a concrete example is to provide the URL of a blog article and request a press release formatted from its content. The agent produces a structured document (title, date, quotes, references) ready to be edited. The PowerPoint agent works on the same principle: from an attached Excel data table, it generates a complete presentation with choice of visual theme and number of slides adapted to the requested level of detail (concise, detailed, in-depth).

Co-work Integration in Copilot Chat

A new tab allows you to switch between classic chat and Co-work, a feature for agentic workflows leveraging your organization's internal data (Work IQ). Co-work lets you plan tasks, customize skills and create reusable prompts.

Key administration points:

• Co-work is not enabled by default, even with a Copilot Premium license.
• Activation requires a request via the "Request access" button, sent to the IT administrator of the tenant.
• Without administrator activation, the tab remains visible but unusable.

Copilot Notebooks Generalized to All M365 Licenses

Until recently, Copilot notebooks required the Copilot Premium add-on. They are now available to all Microsoft 365 licenses, in both commercial and education environments, with gradual rollout underway.

Two formats coexist:

• Light notebooks, accessible from the "Notebooks" side panel on microsoft365.com, with list view or grid view.
• Notebooks integrated into OneNote, which offer more advanced features (reference management, multi-format content creation).

In OneNote for the web as well as in OneNote Desktop, Copilot notebooks now appear in a dedicated panel, alongside classic notebooks. The rollout to OneNote Desktop is effective for commercial tenants; it remains in progress for education tenants at the time of writing.

Starting from a notebook fed by reference files, it is possible to generate directly:

• A PowerPoint presentation based on notebook content.
• A document or spreadsheet.
• A podcast-style audio summary ("audio overview").

New File Types as References and Infographic Generation

Copilot notebooks now accept three new formats as reference files:

• Markdown (.md)
• Plain text (.txt)
• RTF (Rich Text Format)

These formats are added to already supported types and expand the sources available to feed a business notebook.

Another creation available: infographic generation, currently in Frontier early access (Microsoft's early adopter program). From a notebook's references, Copilot produces an information-dense image, visually structured, using the platform's most advanced image models. The generated infographic can be copied to the clipboard, downloaded locally, or pinned as content created in the notebook.

Editing Suggestions in Copilot Pages and Enriched Prompt Lab

Two developments complete this wave of new features:

Editing suggestions in Copilot Pages (Frontier feature, early access): from the suggested actions menu of a page, the "Suggest edits" option analyzes existing content and proposes concrete improvements — prioritization of objectives, addition of time estimates, restructuring into a Loop table. Each suggestion applies individually via an "Apply" button, while preserving the ability to ignore irrelevant proposals.

Prompt Lab (prompt library): accessible from the three-dot menu of Copilot Chat, the library has been enriched with new categories: thematic prompts classified by subject, and agent-specific prompts (analyst, researcher, surveys). Keyword search allows you to quickly find a prompt example suited to a given use case.

Key Takeaways

• The Copilot Chat model selector now exposes GPT-5.6, GPT-5.5, Claude Sonnet and Claude Opus, in addition to Auto mode.
• Word, Excel and PowerPoint agents are accessible via @mention to all Copilot Chat users, with no additional license required.
• Co-work exists in the interface but requires explicit activation by the IT administrator.
• Copilot notebooks no longer require Copilot Premium, except for the audio overview function.
• Markdown, plain text and RTF are added to supported reference formats in notebooks.
• Infographic generation and editing suggestions in Copilot Pages are in Frontier early access.
• The prompt library is enriched with thematic categories and agent-specific prompts.

For IT teams, the priority action is to verify the deployment status of Copilot notebooks on the tenant and to anticipate Co-work activation requests from internal support.