Microsoft announced that starting with the forthcoming November 2022 update (v16.67) to Office 365 desktop applications for Macs, macOS Big Sur 11 or later will be required.  The October 2022 update (v16.66) will be their last build that supports macOS Catalina 10.15.x.

You may view Microsoft's announcement on their website below for more information:
https://support.microsoft.com/en-us/office/upgrade-macos-to-continue-receiving-microsoft-365-and-office-for-mac-updates-16b8414f-08ec-4b24-8c91-10a918f649f8?ui=en-us&rs=en-us&ad=us

As of October 11, 2022, UCSF IT Field Services support Office for Mac v16.66 and recommends users update Microsoft applications on their Macs to the latest supported version as it contains security updates.  We currently do not block Microsoft Autoupdate on managed Macs except for beta channel and previews.  You may follow Microsoft's instructions at the website below to update Microsoft applications on your Mac or wait for our next patching cycle using BigFix:
https://support.microsoft.com/en-us/office/update-office-for-mac-automatically-bfd1e497-c24d-4754-92ab-910a4074d7c1

Release notes and version history for all Office 365 updates for Macs are also available on Microsoft's website at https://learn.microsoft.com/en-us/officeupdates/release-notes-office-for-mac.

For information on how to upgrade macOS for your Mac at UCSF, visit this page for details: https://it.ucsf.edu/news/macos-monterey-ucsf.