There is nothing new about this at all. Websites can collect data and forward it on the backend since the dawn of the internet. Google Analytics has an HTTP API [1] for sending events that's used by plenty of large sites. Consolidating event collection and forwarding to various sources is a large SaaS category with several billion-dollar companies, and one of the biggest success stories is Segment from YC [2].

In past adblocking discussions, many users mentioned that they were fine with ads if they were served by the 1st party without data leakage, but the entire issue is that 1st-party on a technical basis has no bearing on the custody and access of the data itself. The only serious way to protect privacy is through legal doctrine that regulates collection and sharing. Browser-based adblockers were always a short-term technical bandaid to a much broader surveillance problem, but the real solutions take much more work.

1. https://developers.google.com/analytics/devguides/collection... 2. https://www.ycombinator.com/companies/segment