As announced during the Microsoft Ignite conference, during the coming months “Microsoft Office” is rebranded as “Microsoft 365”.
This include Office.com, the Office mobile app, and the Office app for Windows that will become Microsoft 365 app, with a new icon, a new look, and more features. Change for Office.com will begin rolling out in November 2022 and changes to the Office app on Windows and the Office mobile app will begin in January 2023.
As a result of the domain changes, organizations should ensure that the microsoft365.com domain is allowed in any firewall rule or security configuration where the office.com domain is already allowed.
The widely known apps like Word, Excel, PowerPoint and Outlook will still continue to be available. There will be no impact to existing account, profile, or files, and there are currently no changes to Office 365 subscription plans.
Microsoft released a general FAQ concerning the change: https://www.microsoft.com/en-us/microsoft-365/microsoft-365-faqs
The change is also documented in the Microsoft 365 Roadmap as Feature ID 98173