Now it's Worf not wanting to talk about a terrible disease that affected a ton of Klingons and probably caused severe social rifts in his society. Hilarious. Plus, why wouldn't the other Starfleet officers know about this? At the very least, I'd expect them to learn about the augment virus and the state of Klingons, while preparing to go on-board the station.
Plus since it was only a century ago that Klingons looked like that and the Federation is a post Information-Age society, and has species that live well past 100 years of age (among them humans) or 200 years of age (Vulcans) ...it also seriously opens up plot holes about information archives, history and basic memory retention in the Federation.
There is no serious way that the Klingons actually looking like slightly harrier humans smeared with shoe paste in the 23rd century should be able to be a "secret" in the 24th century.