how will actual data not be more informative? you can easily infer what the appointment was because the phone call will mention the name of the doctor or office and you can look that up plus all the details they discuss

you'd still have to look up who the doctor they called is from the metadata; it's still info but absolutely not more informative than the real data

so this line of thought makes no sense, and glenn greenwald should be looked at very skeptically in general, he sounds smart but when you look at his logic closer it breaks down