Apple announced the AirPower along the iPhone X. They didn’t ship it and canceled the whole thing. Apple now look dump. If you want a good perspective on why Apple pre-announced AirPower, I suggest that you take ten minutes to read Steven Sinofsky excellent piece “Pre-Announcing as a Strategy”
The idea of pre-announcing a product at first seems really dumb. When you think about an action like this you often come to a conclusion that anything that seems dumb but happens often probably has some clever, and strategic, use for it. Pre-announcements are no different.