“Upgrading your operating system to macOS 10.14 or later will allow Office updates to be delivered for your apps.
If you continue with an older version of macOS, your Office apps will still work, but you'll no longer receive any updates including security updates,” Microsoft explains. “As of the November 2020 (build 16.43) update for Microsoft 365 for Mac or Office 2019 for Mac, macOS 10.14 Mojave or later is required to receive updates to Word, Excel, PowerPoint, Outlook and OneNote. Microsoft says that Microsoft 365 for Mac and Office 2019 for Mac would no longer receive updates on an Apple computer unless it runs macOS 10.14 Mojave or a newer version. Needless to say, the change doesn’t come as a big surprise, as dropping support for old OS versions is something that happens on all platforms. Microsoft has recently announced that Office 365 apps would no longer run on macOS 10.13 High Sierra as of November 10, as the company is switching the focus to newer operating systems.
