New SharePoint Experience: App Bar Redesign Guide

• MC1240699 replaces the SharePoint start page with Discover and adds Publish and Build to the app bar.
• Public preview concluded May 4, 2026 — standard release is rolling out tenant by tenant through mid-2026.
• The classic-experience toggle only ever existed during preview; standard release removes it entirely.
• Neutral app theming changes background colors across SharePoint surfaces, including SPFx web part placeholders.
• Followed Sites becomes Favorite Sites; Saved for Later becomes Favorites — the underlying data is unaffected.
• Permissions, content, and sharing settings are untouched by this change.

Microsoft 365 Message Center notification MC1240699 is the reason SharePoint tenants are quietly starting to look different this year. Unlike most SharePoint changes, this one is not a feature toggle buried in the admin center — it is a redesign of the primary navigation every user sees the moment they open SharePoint. The classic start page and left-hand app bar are being replaced with a new Discover, Publish, and Build structure, and the visual theme underneath every page is shifting to a neutral palette.

What makes this genuinely time-sensitive is one specific detail confirmed in Microsoft's own documentation: the option to switch back to the classic app bar existed only during the public preview, and that preview concluded on May 4, 2026. If your tenant has not yet reached standard release, you still have a short window to pilot the change, screenshot the new experience for your help desk, and catch anything that looks broken in custom branding. Once standard release reaches your tenant, that window closes.

One-minute summary in plain English

SharePoint's navigation is being simplified around three jobs: finding things, publishing things, and building things. Instead of a general-purpose start page and a left-hand bar that tried to do everything, the new app bar routes each job to its own destination. Microsoft's stated goal is a "consistent, neutral palette" across SharePoint surfaces that pushes customer branding and content forward rather than competing with chrome and iconography for attention.

This is a UI and navigation change, not a permissions or content change. No site, list, library, or sharing setting is touched. What does change is what people click to get around, what your screenshots in training material look like, and — for anyone with custom SPFx web parts — how those web parts sit inside a lighter, more neutral surface.

What the redesigned app bar actually contains

The three new destinations map cleanly onto three different user intents, and understanding that split is the fastest way to explain the change to end users.

Discover — replaces the classic start page

• Refreshed experience for finding sites, content, and news relevant to the signed-in user.
• Followed Sites is renamed Favorite Sites — the sites themselves and the follow relationship are preserved, only the label changes.

Publish — new destination

• Brings together pages, news, and campaign-style communications in one place.
• Saved for Later for pages and news posts is renamed Favorites.

Build — new destination

• A single surface for makers to create and manage sites, lists, libraries, and AI-powered agents.
• Consolidates entry points that used to be scattered across the classic start page and site contents menus.

Global navigation and neutral theming

If your organization has configured global navigation on its Home site, the new app bar shows your logo and name at the top — this behavior is unchanged from the Viva Connections app bar model, just carried into the redesigned bar. Underneath all three destinations, neutral app theming applies a consistent, muted palette across SharePoint UI surfaces, including SPFx placeholders, so that your content and branding read more clearly against a quieter backdrop.

Rollout chronology

How to check and pilot the setting today

If your tenant has not yet moved to standard release, you can still control the timing and run a pilot.

1. Open the setting above and review whether your tenant already shows it as active, pending, or available to enable.
2. If it is still available to enable and preview has not concluded for your tenant wave, turn it on for a pilot group first rather than your whole organization.
3. Walk through Discover, Publish, and Build yourself and capture screenshots for a help-desk one-pager.
4. Open your two or three most heavily branded Home sites and pages to check how they render under neutral theming.

What to visually audit before rollout reaches you

Because neutral theming changes background and surface colors rather than site content, the risk is cosmetic, not structural — but cosmetic problems on a heavily branded intranet still generate tickets.

Operational plan you can use immediately

This is a Microsoft-driven rollout, so your job is readiness and communication rather than a migration project.

Stage 1: pilot and audit (if preview is still available)

• Enable preview for a pilot group of power users and site owners.
• Screenshot Discover, Publish, and Build for help-desk reference.
• Visually check top Home sites and heavily customized SPFx web parts under neutral theming.

Stage 2: communication before standard release

• Send a short, non-technical notice to all users describing what will look different and when.
• Update onboarding material and internal documentation that references old navigation labels.
• Brief the help desk on the Discover / Publish / Build split and the Favorite Sites / Favorites renames.

Stage 3: post-rollout monitoring

• Track "where did X go" ticket volume for the first two weeks after rollout.
• Fix any SPFx web parts that visually clash with neutral theming.
• Confirm global navigation branding still renders as expected once the change is live for everyone.

Troubleshooting playbook

Direct answers to common admin questions

1) Do we need to do anything, or does Microsoft just roll this out?

Microsoft drives the rollout itself through standard release. Your actions are optional readiness work — piloting, auditing branding, and communicating — not a required migration step. If you do nothing, the new experience still arrives.

2) Will this break any of our automation or scripts?

No. This change is limited to navigation, the start page, and visual theming. It does not touch SharePoint's underlying APIs, PnP PowerShell operations, Power Automate flows, or Graph calls against sites, lists, or libraries.

3) What about multi-tenant consulting environments?

Track each client tenant's rollout phase separately using the admin center setting. Tenants that enabled preview early may already be past the toggle-back window; tenants that never opted in will hit standard release on Microsoft's timeline regardless of your involvement.

Simple explanation for business stakeholders

Communication template you can send internally

Subject: SharePoint navigation is getting a refresh

Microsoft is rolling out a redesigned SharePoint navigation bar (MC1240699).

What changes:
- The start page becomes "Discover" for finding sites, content, and news.
- Two new areas appear: "Publish" (pages and news) and "Build" (creating sites,
  lists, and libraries).
- The overall look becomes cleaner with a neutral color theme.

What does NOT change:
- Your files, permissions, and site content are untouched.
- "Followed Sites" is now called "Favorite Sites" - the same sites are there.

Support:
If anything looks broken or you can't find something you used to see,
contact <support mailbox> with a screenshot.

Mistakes to avoid during this rollout

• Assuming you can defer indefinitely: standard release does not require an opt-in action from you.
• Skipping the branding audit: neutral theming is subtle until it clashes with a hard-coded custom web part.
• Waiting until go-live to write help-desk material: the preview window is the cheapest time to capture screenshots.
• Telling users they can toggle back: that option existed for preview only and will confuse people if promised after the fact.
• Treating this as a permissions or migration project: it is a navigation and theming change only.

Final checklist before standard release reaches you

1. Check the SharePoint admin center setting to see your tenant's current rollout status.
2. If preview is still available, pilot it with a small group and capture screenshots.
3. Visually audit top Home sites and custom SPFx web parts under neutral theming.
4. Update onboarding docs and help-desk scripts to reflect Discover, Publish, Build, and the Favorites rename.
5. Send a short internal notice before rollout, not after.
6. Monitor ticket volume for two weeks post-rollout and fix cosmetic issues as they surface.

Complete these six items and this becomes a smooth cosmetic update instead of a wave of "where did it go" tickets.

Reference links

• Microsoft Learn: New SharePoint experience
• Microsoft Support: About the SharePoint app bar
• Microsoft Support: Discover in SharePoint
• Microsoft Support: Publish in SharePoint
• Microsoft Support: Build in SharePoint
• Microsoft Learn: Global navigation in the SharePoint app bar