I searched, and couldn’t find anything too. The only official docs I could find about Health app are these, and they don’t have any relevant [to what we are talking about] info: Health Privacy Overview Health App & Privacy
To be honest I haven’t found any sources that explicitly say that Health app is opt-in… Only mentions of Apple Research (“which allows iPhone users to participate in years-long health studies being opt-in”), and Improve Health & Activity (sharing Health data with Apple) is opt-in too.
Do you mean you tested this yourself (did you factory-reset your device, etc)?
Are these enabled by default when you set up your phone for the first time (after buying / after factory reset, etc)? I mean: do these features collect data automatically (and without a prompt) after setting up the phone?
Assuming you are talking specifically about the health data
In the case of:
The 3rd party app: NO (it is an app I manually installed and consented to sharing data)
Settings: Probably NO (the only data that came from this was sleep schedule, which is not setup until you set it up manually and it does indicate you can “view your sleep data in the health app”, also it doesn’t really seem to track your actual sleep pattern, its more like the sleep schedule you ASPIRE to have)
The Fitness App: I very vaguely recall being presented with T&C when I first opened the fitness app, but I could be wrong, its been a while.
I have an old iPhone, I’m going to factory reset and do a little testing in the next few days, I’ll write an update if I find out anything worthy of reporting here.
Meanwhile, the Pixel 9 series is set to expand. Alongside the regular Pixel 9 (no codename on this) and the Pixel 9 Pro (“komodo”), Google wants to launch a small version of the Pixel 9 Pro. At 6.3" this model (codenamed “caiman”) would effectively be the size of the current Pixel 7, but with all of the extras that often leave users opting for the larger model. It’s yet another Apple-inspired move, as Google looks to chase the success of phones like the iPhone 14 Pro and Pro Max.
Ultimately that’s on Google to figure out (and I hope they do). As a potential customer all I know is I want a phone that fits in my pocket and doesn’t hurt to use.