I was thinking how the hell does an app track another apps' activity? So they allegedly used AppsFlyer, which is a Mobile Measurement Partner (MMP).
Companies like Grindr use it for tracking ads, it basically tells whether a user that clicked on a Grindr ad on Tiktok lead to a successful install of their app. They have to install an SDK for that. Apparently it wasn't just tracking that.
I don't think so. From what I gathered, the only thing Play Services can see on GrapheneOS is the list of other apps you have installed. That's it. They can't see anything else unless you grant access to it. You're not giving Google root access to your phone, you're just installing an app that happens to be made by Google, and it's locked down like everything else.Edit: https://youtu.be/YB01HHFitFA?t=625 I just saw this video apparently apps can still communicate with each other so you might want to isolate if that's something you're worried about.
Edit 2 : Another relevant link https://discuss.grapheneos.org/d/28558-google-can-still-see-my-app-activity-on-grapheneos/2