As pointed out by MacRumors, Apple has added the ability to hide iCloud Keychain security recommendations in the latest beta of iOS 15.4. Previously, there was no way to hide security recommendations other than turning them off altogether.
In iOS 15.4 beta, any security recommendation listed in the Passwords section of the Settings app can be hidden. All you need to do is tap into an alert and then tap the new “x” button next to any security recommendation that you want to hide from view.
Security alerts that have been hidden will no longer show up under the main “Security Recommendations” label.
“You can still view them if necessary by opening up the Passwords interface and scrolling down to the bottom where there’s a new “Hidden Security Recommendations” option.
In this section, you will find any password alerts that have been hidden from your view.”
The new feature can come in handy for passwords that you cannot change for some reason, such as when the password belongs to someone else.
The latest iOS 15.4 beta also lets you add a note to any iCloud Keychain password to provide yourself with more context on a password.