Macworld:

Microsoft has warned users of Office for Mac 2011 not to upgrade to Apple’s macOS High Sierra when the new operating system launches next month.

“Word, Excel, PowerPoint, Outlook and Lync have not been tested on macOS 10.13 High Sierra, and no formal support for this configuration will be provided,” Microsoft wrote in a support document.

In the same document, Microsoft told those running the newer Office 2016 for Mac that they must update its applications to version 15.35 or later, if they intend to upgrade their Macs to High Sierra.

Microsoft’s advice about Office for Mac 2011 wasn’t unexpected, since support for the application suite is slated to end Oct. 10, a date Microsoft first stamped on the calendar two years ago, but has not widely publicized since.

Office isn’t officially dead on the Mac but it might be on life support.

UPDATE for clarification (not that it will help): Fewer and fewer Mac users use/need/want Office. At some point, Microsoft will face diminishing returns in their effort to support, sell and develop the software. That point may be coming sooner rather than later, in my opinion. My apologies for not more clearly stating my point in the original post.