https://marketingland.com/apples-latest-itp-updates-what-mar... suggests that "When a user loads a web page with embedded content from another domain, as in a tracking pixel, the request header referrer for the tracking domain will no longer contain the full web address of the host page, only the domain name." This is the case when "Prevent cross-site tracking" is turned on.
Not the same thing as hiding your IP and the domain name, but we're getting closer to full privacy, slowly. The problem with proxying is that it would only work with a small list of third-party asset hosts, and it would break the ability for CDNs to work unless it was a distributed proxy... that sounds like more headache than its worth except maybe as a new type of browser extension, something similar to a content filter but instead loads cached or proxied copies.
But at that point it's worth considering VPN or compression proxy services for content compression as Chrome and Opera Mini might do, and MITM everything the browser loads so nobody gets your IP except Apple. I imagine folks might pay for an Apple VPN service, I'm just not sure Apple wants any headaches that might go along with it yet. :)
> the request header referrer for the tracking domain will no longer contain the full web address of the host page, only the domain name
Why not just remove referrer header for all 3rd party requests? Or remove it in Private browsing mode. VPNs nice, im using one, but other VPN companies are not, such a cutthroat business :) And you can not self-host VPN, it defeats the hide my IP feature.
https://wiki.mozilla.org/Security/Referrer