I think people are too focused on the device part of it.

Whatever Apple did to block access to the cache does not negate the fact that these notification messages are still being sent in plaintext through Apple and Google’s servers.

It’s hard to imagine that Apple/Google couldn’t just be compelled to hand this information over if ordered by a court and wouldn’t need your phone at all.

And this loophole possibly only hinges on the fact that most law enforcement maybe never realized this was something they could ask for.

Or perhaps this is happening and the public just doesn’t know it yet.