Please don't be fooled. If you look at the table in the article, you'll see that there are several categories of data that are not end-to-end encrypted, like Contants, and the reason for that is probably because US government and courts want to have them, even for non-US citizens. Otherwise why not encrypt them too?

It would be fair if Apple gave a warning about US governments and courts before enabling sync to iCloud, but I guess they don't want users to know about it.

Also this is a closed source system, so we can't know whether Apple can remotely extract encryption keys or not.

Also as I understand, Apple now demands a phone number to sign up for Apple ID, so it means that now all users and their contacts are non-anonymous for Apple.