That would be such a disgusting move I'd sell all the apple hardware I own right away.
If I did want to cook up conspiracy theory, it would be easy: Apple wants to distract from the fact that NeuralHash was broken by researchers. This project apparently is able to create CSAM collisions:
https://github.com/AsuharietYgvar/AppleNeuralHash2ONNX
If NeuralHash is really rolled out, and if this python project can really create collisions, the CSAM system could be DDoS'd by people on their own computers, jamming up Apple's internal censorship review system with false positives. Hence, Apple would be incentivized to sweep this under the rug by "delaying" rollout indeterminately.
There is so much network traffic between macOS services and the internet, I'm not sure how easy it would be for researchers to discover if CSAM reporting is enabled. Little snitch detects 292 macOS services on my M1, all talking to the internet. Network experts in Apple probably even have ways of bypassing little snitch.