Following the Directions makes the Cura damaged. Are you going to update it? Have any remedies to fix?
This worked for me on Catalina.
Follow all indicated steps to install and patch Cura up to the moment where you open it and get the error message the package is damaged.
Dismiss that error.
Open a terminal window and execute:
sudo xattr -rds com.apple.quarantine /Applications/Ultimaker\ Cura.app
You can now open Cura.
Enjoy!