The same benefit they had when they were two stepping all around the Anthrax letters. Trying to avoid a panic. Can't let the dirty mob know what's really going on. Thinking like that got two postal workers killed. The Airlines and the gov't want to do everything possible to keep the public flying through the holidays.
Anthrax info was trickled out one drop at a time, one drop a day over three weeks in an effort to minimize panic.
The Fedgov has a motive to minimize today's happenings. Any further hits to the airline industry could really hurt the US economy.
If I were in their shoes, I may do the same thing.