Your Mac has a property list file (plist) that controls what appears in your Dock. If a macOS update changes the name or location of an application, the plist updates the Dock. If a macOS update removes an application or adds new major features, the plist may remove the application from the Dock.
Use an alternative plist
You can use a configuration profile to set an alternative plist. In the profile, set the AllowDockFixupOverride key to true in the com.apple.dock domain.
The Apple provided plist is located at /System/Library/CoreServices/Dock.app/Contents/Resources/com.apple.dockfixup.plist. You can put a modified copy of this file in the /Library/Preferences folder.
If the configuration profile is active and the com.apple.dockfixup.plist file isn’t located in /Library/Preferences, the original plist and customized plist settings won’t work.
If the application is renamed, moved, or removed
If an application name changes, an application is removed, or if the location of an application changes, the original plist updates the Dock entries. If you use a customized plist, you may see question marks in the Dock after you update macOS. This happens if the customized plist can’t find the linked applications.