A British man is ridiculously attempting to sue Apple following a divorce, caused by his wife finding messages to a prostitute he deleted from his iPhone that were still accessible on an iMac.
In the last years of his marriage, a man referred to as “Richard” started to use the services of prostitutes, without his wife’s knowledge. To try and keep the communications secret, he used iMessages on his iPhone, but then deleted the messages.
Despite being careful on his iPhone to cover his tracks, he didn’t count on Apple’s ecosystem automatically synchronizing his messaging history with the family iMac. Apparently, he wasn’t careful enough to use Family Sharing for iCloud, or discrete user accounts on the Mac.
The Times reports the wife saw the message when she opened iMessage on the iMac. She also saw years of messages to prostitutes, revealing a long period of infidelity by her husband.
They explain how this works in their “tips” app - ie the user guide.
You seem to think that because you expect something to work a certain way, everyone does, and that’s just not true at all. For most of the history of iMessage, they were never synced. Eventually they rolled out the option to sync them with iMessage for iCloud. You can choose to use it or not. But I would suggest that just as many people think that deleting a text from one device won’t delete it from the others.
This is not the case of “apple” storing the message anywhere. This is the case of a user storing his messages locally on his Mac and then sharing the account with his wife. He’s clearly an idiot, but sure, blame Apple for not being able to save him from himself.