What's to "prepare" for shutting it down? Reminds me of the story where John Coltrane told Miles Davis that he didn't know how to end his solos. Miles said: "Try taking the fucking horn out of your mouth."
They'll probably try to do this as sloppily as possible because as long as they can claim surveillance of US people is unintentional, it's legal under FISA 702.
'alter table Panopticon drop column Country;'
But yea, it should be as simple as a switch, the rest is just after effects, you're right.
What they're really doing here is what bureaucrats always do when you tell them they can't do something - this is the first step in a PR campaign to scare people into forcing Congress to reauthorize expansive data collection.