Wait what? So 10 screens of bangers like "An app may be able to execute arbitrary code with kernel privileges" and "An attacker with arbitrary kernel read and write capability may be able to bypass kernel memory protections. Apple is aware of a report that this issue may have been exploited." are not considered smoking guns?
The signal raised for page faults should be (and actually was, before 14.4) SIGSEGV, and not SIGKILL. This behaviour is even defined by POSIX.
There is no reason why this should change, specially not in the final release instead of in the public betas and early access releases (where the change was not present).
The former would be a catastrophic defect and probably result in the release being pulled from distribution.
The latter would be a new classification of certain kinds of page faults as “safe” and “unsafe”, and only the safe ones are allowed to comply with POSIX signal handling. Perhaps they’ll propose an update to POSIX now that the zero day response has shipped.
Why is preventing trapping on an illegal memory access a sensible security practice?
Preventing the access, sure, but I'm not seeing what force killing a process does for security, especially given there are perfectly reasonable reasons why one might want to trap the signal.