I always kind of assumed that they worded it in such a way to prevent you from indicating it in any way, specifically to avoid this loophole. They're not stupid, after all. But like the article says, forcing you to lie might get a bit tricky, legally speaking.
Anyway, assuming this is possible, how would one for each user work? You (an admin) simply click a button every day that updates the timestamp on all profiles, excepting the ones you were contacted about?
At this point, it might help raise the profile of both the tactic and the site a bit. Could be interesting to watch how the policy develops across other sites and institutions.