My understanding is that private relay only (for now) relays plain HTTP content from apps, and HTTP+HTTPS content from Safari. This means it likely shouldn't (

My understanding is that private relay only (for now) relays plain HTTP content from apps, and HTTP+HTTPS content from Safari. This means it likely shouldn't (currently) affect zero rating for apps, though it would affect header enrichment for first-party web based services. A native app shouldn't be affected, and given most services run on HTTPS, they won't be able to add headers to those requests anyway. The impact of losing visibility of plain HTTP is likely minimal given how much is HTTPS now. The impact of losing visibility of sites visited and DNS queries may impact on carrier 'value add' services like internet filter, malware protection, etc. Also it would be harder to link location based services in for web-based content, as they can't correlate the browsing session with the phone user. If Apple was to expand this to cover HTTPS traffic via apps, that would break a lot more. Carriers are desperately clinging to ways not to become dumb pipes, so it doesn't surprise me to see them resist these moves.