Priorities changed - Pitched
Most developers know that task switching is a great way to destroy productivity. In essence, it's the same when the company changes priorities at the last minute. All the preparation is wasted, all the coordination goes out the door and you're back at starting blocks. There exists a “last responsible moment”, after which changing the focus for development team will be wasteful. Of course, occasionally this change and waste is better then the repercussions of not, but in my experience this is rare. The idea of suddenly changing priorities is usually based on incomplete information. Anything that improves communication, so that everyone is fully in the know, is good.
Tip: Try to ensure the stakeholders who can change priorities are a) aware of the last responsible moment b) are in the right meetings c) are aware of the potential loss of productivity.