This is all only mentioned in the footnote of an iCloud security document [1].
Apple cares about your privacy, so much that they made a backdoor through bad defaults, well in reach of the CLOUD Act.
[1] Footnote 9 in https://support.apple.com/en-us/102651
Most people don't even understand that when their favorite app that says E2E that that app still has access to the clear text before it's encrypted...