Even if that's true, this method at least drops some part of the process on the client where it can be inspected, vs. all scanning happening in the cloud, entirely behind closed doors.
Does that mean nothing bad can happen? No. But it does mean that when something changes, we at least know something changed.
The database will change every update. It’s not like the NCEMC db already has all possible CSAM. Every time they find more, they add it to the DB. Thus, it will probably change every time Apple pushes an OS update.
Does that mean nothing bad can happen? No. But it does mean that when something changes, we at least know something changed.