Points 2 and 3 seem to be a denial of reality: you never can delete something except by asking everyone else very nicely, and it's always possible that someone will repost something that they had that you didn't think they did.
Likewise point 8: there's nothing a protocol that isn't just a walled garden for a set of Trusted™ proprietary client binaries can do to prevent a client from doing whatever it likes with the decrypted information.
There are no absolutes in security.
It’s not a perfect control by means, but if your objective is to minimise the amount of sensitive material just laying around, it definitely helps (and makes your adversary’s life a bit harder.)
Does anyone understand the security concerns here? The satellites can still be tracked and intercepted even with the feed unplugged so what does this really accomplish?
Navy receives data from the spacecraft, pushes that up into their probably-classified HPC environment, processes it there and then gets the output back into the unclassified world via a cross domain solution[1] of some sort.
High-to-low CDSes in particular are very expensive and complex to deploy and obtain approval to operate, so it makes sense that they’re reluctant to spend a ton of money and resources doing that as part of their modernisation work to support a spacecraft that they plan to decommission anyway.
[1] https://en.m.wikipedia.org/wiki/Cross-domain_solution