I basically agree with you, but also am not sure how to square this with my belief that we are really gathering way too much information as a society (it always leaks).
you smoking a cig in an alley on your 15 minute break? you should have every right and privilege on earth.
you running 10,000 person strong group of people with the legal right to use force against your fellow man fighting to deny people their personal liberties with a long history of corruption? i don't care if there's cameras in the bathrooms.
I think a good starting point for squaring this is to examine it in the context of what else the administration is doing (or not doing) to protect the privacy of citizens. This move has an enormous deleterious effect on police accountability in exchange for a fairly small increase in citizen privacy, so if the administration is ignoring more effective ways to improve the citizenry's privacy you can safely infer what really motivated their decision to back away from body cams.