It was removed as a part of a general thrust towards removing shady VPN apps. Onavo the VPN app that’s mentioned in the post was also removed from the App Store around the same time. The article is trying to spin the narrative of a causal connection between Apple removing their app from the App Store and then introducing the same feature in iOS, but that doesn’t seem to be the true.
Put a different way, they temporarily allowed this horrifically implemented app until they had a first party solution which wasn't a privacy dumpster-fire.