User blog comment:Halo1081/Chapter 128 and forward/@comment-4911196-20150302030909/@comment-5707992-20150302032227

I don't think the chairman nor the Ministry of Defense actually know about her. If Shiro didn't know her, why would they?

Also Korosensei is, by technicality, a state secret. Yes, the world leaders may know about him, but ultimately it stays in Japan.