Earlier quoted context omitted.
This is what I’m interested in. Article itself did not mention cross site tracking. Every website having their own tracking subdomain makes third party cookies not work cross site even without browser changes.
yes, they would need to get another identifier, and that's what is done with players like Facebook. Sorry another of my articles in french: https://pixeldetracking.com/fr/les-signaux-resilients-de-fac... , but Facebook is making it easy to integrate their "Conversion API (CAPI)" with GTM Server-Side tagging
It should not allow e.g. Facebook to link your activity on a news site to your Facecbook cookie, because while you're on cnn.com, your browser is using the cnn.com-specific cookie jar for everything, including the like button?