If they can decrypt in a “specialized” situation, then they can decrypt in any situation. All that has to be done is to broaden the classifier step by step. Or someone else gets access to the back door. That’s why there can be zero allowed back doors.
The database ships with iOS. Apple can do anything they want in iOS updates. In fact, this was exactly the “back door” the FBI requested Apple use half a decade ago. Per this standard, all Apple end to end products are already backdoored, and nothing new was announced.
Yes but previously Apple’s stance was, “no we won’t do that”. And so they earned many’s trust. Now they are planning to do exactly that. And so they have broken the trust they earned.
Where specifically did Apple say they will never try to detect for the presence of CSAM in your iCloud Photo Library? In fact, people mistakenly assume that they do already.