I think you're conflating two very different scenarios. Someone saying "I'm in San Francisco" or posting a picture of them at the Golden Gate Bridge is clearly aware that their location can be determined. EXIF data hidden within a JPEG file is not so clear cut and most users are unlikely to be aware of it.

As you said, Location Services and Photo access are different permissions. Users are therefore likely to assume that location data is not being retrieved if they deny permission to it. If I deny location data to an app, it's because I don't want that app to have my location data. It seems somewhat underhanded, to me at least, to assume that the user wouldn't mind me accessing location data from their photos, knowing full well that the majority of users will not know what EXIF data is. I'd go so far as to say that I would explicitly ask the user if EXIF data should be read alongside the standard location services.