I thought about this same thing today. Before logging in any more, I snapped the entire game folder.
Some may think its paranoid, plus they wouldn't dare break our post-11/30 -demoplay just to ensure no service emulators work, right?
Well, remember it isn't very farfetched to imagine a last-minute patch to disable your client's ability to connect online to an unofficial service (which -demoplay doesn't need to do). They could effectively neuter the netcode path and still leave local -demoplay working.
And as outlandish as it sounds, I don't trust it not to happen enough to take a chance with my only copy of the game in its fully patched and current form.