This happened so quickly I suspect there was never a decision for or against. Pretty likely a boneheaded engineer did what us boneheaded engineers do and cut corners, likely with all of the fun boneheaded management and deadlines that come along for the ride.
Why, you might ask, would this be a matter of cutting corners? Well, fault tolerance is hard. What happens when the OS can’t reach external services it depends on for security features? Well, Apple found out recently in quite an embarrassing way. Given the almost immutable yearly release cycle, I would be astonished if they didn’t just duct tape some whitelist in because a more resilient solution wasn’t ready.