Apple has released the macOS Catalina Supplement. According to Apple’s release note it includes installation and reliability improvements, and is recommended for all users.
Apple says the update:
Improves installation reliability of macOS Catalina on Macs with low disk space;
Fixes an issue that prevented Setup Assistant from completing during some installations;
Resolves an issue that prevents accepting iCloud Terms and Conditions when multiple iCloud accounts are logged in;
Improves the reliability of saving Game Center data when playing Apple Arcade games offline.
To download the macOS Catalina Supplement, open the System Preferences app and choose Software Update.