AdventureTenseApple likes to do this. A sort of wink-wink to law enforcement. Obviously, law enforcement knows all about this already.
They got into trouble for sharing unencrypted notifications with law enforcement/gov, and as far as I know, notifications in ios are still not encrypted.
I don't think this is by accident.
Apple Stops Weirdly Storing Data That Let Cops Spy On Signal Chats - Slashdot
Apple has fixed a bug that could cause parts of Signal notifications to remain stored on iPhones even after messages disappeared and the app was deleted. "Affected users concerned about push notifications can update their devices to stop what Apple characterized as 'notifications marked for deletion...