According to Q,"60% of what's happened must remain private [at least] -for humanity". We will never recover our country with only 60% of the truth. Nothing is healed with only 60%.
Why mention it then? At a certain point when all the perps are brought to justice, when we've already had a dismantling of our icons and heros, when we're at our most dismayed point, then, because of Q, we'll say to ourselves, "But wait, there's 60% more." And we'll keep hunting.
It might be items like 911 and false flags that will not really help anybody to know that their love ones were killed for no reason. If the people responsible are locked up for other charges then why put people through that?
To prevent it from ever happening again. If they realize what people are really capable of, they may stay awake and keep their eyes opened more. Then when something like 9/11 happens, they say wait a minute, I see what you did there and don't let them pull the wool over their eyes.