No, you're good, and we're mostly on the same page! My general expectation is that your server tries its best, maybe there are still copies out there, but you shrug and say "eh, I wiped my stuff locally, good enough".
But yeah, I agree that once something leaves your server in terms of the passage of data, there are no guarantees. And I do agree that significant structural changes are necessary and important for the network's continued evolution!