They will not be able to reliably tell their users if the end user landed on the page, and most importantly, specific users. They will only be able to guess. To

They will not be able to reliably tell their users if the end user landed on the page, and most importantly, specific users. They will only be able to guess. Today, the tracking mechanism works in tandem with the facebook pixels or tracking scripts on the receiving end to give full E2E campaign clarity. This will break that, or at least introduce heavy uncertainty that will definitely impact their revenue model.