Why are there so many already de-orbiting and burning up?
They put them up 60 at a time. My guess is they'll deorbit the first 2 or 3 batches as they were all pre-production test articles. I believe they're on launch 13? They're reusing old Falcon 9 boosters, some of which have been landed and used 5+ times already as the method to get the launches done. At the current pace, they're doing a launch every other week or so.