With the official release of Big Sur today, we're pleased to provide day one support with Office 365/2019 apps. For the best experience on Big Sur, upgrade to the 16.43 release that went live on November 10.
Also note that 16.43 will be the last release to support 10.13 High Sierra. Next months' 16.44 update will only be offered to devices running 10.14 Mojave or later. This is consistent with our N-2 support policy for macOS support.
For those of you interested in Apple Silicon and the new M1-based devices, our production builds are currently supported under the Rosetta 2 translation layer. We are working on moving our builds to Universal 2 binaries where we will support both x86_64 and arm64 natively within the same app bundle. We have builds available in our Beta Channel - more info and download links here.
Please let me know if you have any questions.
Office for Mac Engineering