The root's observation is that it doesn't use the machine configured DNS. The overwhelming majority of VPNs also don't use the machine configured DNS. Maybe not "any", but if you're using a VPN you're generally going to want your DNS going over it as well.
But it is worth noting if you're on a corporate network, or if you use a DNS solution like NextDNS -- when you turn on PR those no longer play a part, at least to Safari traffic.
I use NordVPN. It specifically has an opt-in setting to use locally discovered DNS in favor of their in-network DNS. This is crucial since out-of-network DNS can leak activity.
I’m not sure what kind of network you believe I described, but would be useful to have a clearer explanation from you.
It is for any VPN client that routes DNS traffic through the VPN as well as HTTP and other web traffic. It's not out of the ordinary for this to happen.
