No, but it’s generally a good indication. If Apple says they can’t access it, and outline the cryptographic methods used to make sure they can’t access it, and it’s been verified by third parties that if you loose the keys (access to your Apple account) then you loose the data, then I’d probably say it’s pretty good evidence that Apple isn’t lying about their implementation.
I’d love to see some evidence that I’m wrong. No one else has been able to provide any.
Absence of evidence is not evidence of absence
No, but it’s generally a good indication. If Apple says they can’t access it, and outline the cryptographic methods used to make sure they can’t access it, and it’s been verified by third parties that if you loose the keys (access to your Apple account) then you loose the data, then I’d probably say it’s pretty good evidence that Apple isn’t lying about their implementation.