When UTM parameters are stripped from a URL by Link Protection, does GA4 still see the referrer data? Or would it always class the traffic source as Direct?
We don’t have GA4 setup server side yet - and I don’t think that would actually change the outcome here - but we’re not seeing growth in Users/Sessions from Facebook even though Facebook’s reporting is showing clicks and conversions. I’m aware Facebook greatly over-reports but to see such little attributed data in GA4 is prompting plenty of questions from stakeholders,
GA4 determines the source of traffic by UTM parameters if they are present, if they are not, it looks at page referrer, if it is empty, then such a visit will be considered as direct.
So yes, if utm were removed in any way, but the transition was for example from Google, most likely by referrer such source will be as Google organic.
The increase in server side conversions in the case of GA4 depends largely on the number of adblockers in your audience. I have had examples when there was no significant increase (+ about 5%), but there were for example sites selling microprocessors, which is visited by an audience that more often uses adblockers - in this case the increase was about 35%.