Those aren't permissions it requests, it has no permissions by default. Instead it's the broadest interpretation of data it could gather from any of its features and dependencies (an app granting a permission grants it to all frameworks as well). But they will have to ask about all of them, especially health data. I wouldn't be surprised if this was a broad, general list they imported from other Meta apps in the rush to ship.
It's not even anything about features or frameworks or dependencies.
It's literally just checkboxes inside App Store Connect when you submit the app.
Basically it's what Meta's lawyers think needs to be disclosed.
I'm sure they do sentiment analysis on your IG posts, put you in advertising targeting cohorts like "cancer survivor", and that's what they mean by "health data". Not that it's getting anything from the iOS Health app.
If I'm posting all day on Threads about my health, that doesn't sound like "Collection of the data occurs only in infrequent cases that are not part of your app’s primary functionality", and hence they need to declare literally anything a user might be posting about.
I'd be surprised if it actually requested it. At the same time, it could just be an overly broad interpretation of the fact that they obviously gather any health data you post about on the service.
Not really the benefit of the doubt given the app is out and no one has posted about it asking for health permission (AFAIK). Or any other permissions you wouldn't expect for social media (again, AFAIK).