Anyone that believes Apple will stick to their script of only scanning what they said they will scan needs to have 'FOOL' tattooed on their forehead because it is a well known fact that tech companies lie not only to consumers but to governments. Google, Facebook, Apple, Microsoft, Amazon have all been caught out at one time or another lieing, sometimes on numerous occasions. It's in a companies nature to tell the comsumer they are doing one thing when in fact they are doing the complete opposite.
A few months or even a year or years from now, icloud users will start to complain that their stored pictures have been erased and Apple will deny it's their fault. Then some security researchers will get involved and they will report that Apple's CSAM scanning as quietly been scanning everyone's icloud account and been accidently erasing users pictures due to a glitch with the scanning process. Then people will say 'hold on Apple, you said you wasn't going to do this type of invasive scanners on users icloud accounts'. Apple will then issue a PR release saying 'sorry, we will update our procedures so something like this does not happen again'.
It's going to happen, you just know it will