Perhaps to get the street interested in what a fine quarter GLW is having. A little pre announcement kind of thing. Maybe they decided to help the share price a little. They sure didn't warn. I think it was a calculated move on their part to generate interest.
Nothing surprises me in terms of how the market is reacting to news right now....PM beat by 29%, guided up, announced huge buybacks and only managed to get a 3.5% jump while others have announced misses with pessimistic guidance and gained 5%.