That isn’t correct, nor is it credible.
See: https://www.apple.com/child-safety/pdf/Security_Threat_Model...
See: https://www.apple.com/child-safety/pdf/Security_Threat_Model...
Either way, if the claim is that it’s possible to reverse engineer CSAM from the hashes, proof is needed, and nobody has provided even a proof of concept.
The person I responded to was claiming it had been demonstrated. I asked for a link to evidence. You just made a hypothesis about how it might work. That’s not helpful.