Purchase History will be for checking if you've purchased the ad-free unlock. (maybe carried over from BoostForReddit too? Not sure.)
Location is usually less about your location and more about your wifi network. Knowing when to refresh the connection due to network switching or performing actions based on what network you're on.
Your location can be determined from your wifi info + databases of networks that google/apple/microsoft each provide/maintain so location permissions are required to see that info.