Interesting, but Senators, Presidents and others in government have had elaborate fortified bunker-type retreats and evacuation plans since the Cold War started, and probably even years before. I wouldn't put any ominous meanings into it.

As for asteroid warnings, unless the asteroid is so far off or so dim that only giant telescopes can locate it, it's just as likely that one or more amateurs will find it first, and as far as I know, they haven't signed up to any secrecy conspiracy. Heck, I wouldn't even count on the guys running the giant telescopes to keep quiet.

Some people really have no idea how hard it is nowadays to keep a secret.