That is a convenience feature. When an app requests access to one of those folders, it will display a dialog asking if you want to allow it. You can allow access or deny. Whatever your choice is, your choice will then be added to that list in System Preferences. If you change your mind about an app later, you can change the behaviour using this list. You can also delete an item from the list entirely and the next time the app needs access to a protected folder, it will have to ask again.
The only way to pre-approve an app for access is to manually add the app to the “Full Disk Access” list.