While the 16.58 release cycle was "Excel-heavy," Word benefited from the underlying Office platform updates:
Some users noted sudden slowdowns. A common fix was disabling "Check grammar as you type" or performing a "Safe Boot" to reset system caches. Community Perspectives Microsoft_Word_v16.58.dmg
“For some reason AutoUpdate is unable to complete the download... since everything else updated automatically, you can update Microsoft Word manually.” Microsoft Learn Important Security Note What's new in Word 2021 for Mac - Microsoft Support While the 16
Continued refinement of the Mac-specific Ribbon interface to align closer with the Windows experience while maintaining Retina display clarity. since everything else updated automatically, you can update
Some users reported that Microsoft AutoUpdate (MAU) struggled to complete the 16.58 download due to network congestion or server-side issues.
“Word wanted to update while I was editing a document, so it restarted. Now I'm not able to use Word for more than 2 min before it's not responding.” Microsoft Learn
Optimized auto-save and version history tools for documents stored on OneDrive or SharePoint. Performance & Known Issues