The "legal" section talks about local scanning, and possible transmission of CSAM from devices to Apple, in pursuit of verification, however Apple have made clear that the scanning happens only for files that have been uploaded to iCloud Photo Library -- in which case they are not deliberately transmitting the CSAM but rather flagging something which the user already sent them.

Likewise the copyright issue; The user has already sent these files to Apple themselves by enabling iCloud photo library, and Apple are not making any additional copies that I am aware of.

It also says "The problem is that you don't know which pictures will be sent to Apple." - but we do know exactly which pictures will and will not be sent to apple; the ones that are already sent by iCloud Photo library.

[To be clear, I don't like the precedent/slippery slope that this kind of technique might lead towards in the future, but it doesn't seem like all the criticisms of it today are valid]