A good way to figure out whether this kind of claim is marketing bullshit, is to look for a PR claim that goes the other way: that Apple or whoever helps the FBI find uploaded images of child sexual abuse. If they are matching on your data, they can’t be encrypting it; if they’re encrypting it, they can’t be matching on it. It’s one or the other.

And, well, Apple have confirmed that they‘re matching on your data[1]. So, guess what?

[1] https://www.scmagazine.com/home/security-news/apple-scans-ic...