Yes. Again, when one sees illicitly disclosed intelligence, there is a lot that intelligence services can determine by having access to that information. They can figure out what the source of the information is. They can figure out who, potentially, would have been seeking the information in the first place, thereby compromising individuals within the security and intelligence community themselves.
Once intelligence services acquire that knowledge, they can develop strategies to avoid similar tactics in the future. When they avoid those tactics and those tactics evolve, the ability for security and intelligence services to maintain access and to have transparency and visibility into what they are doing—whether through human sources, as happens for organizations such as CSIS, or through signals intelligence, if there's disclosure—is closed, because then targets of that intelligence collection can modify their behaviour in a way that closes that ability.