A few hours ago I received an email from Delta in regards to update to Skymiles. The email reads:
Over the past year, more than 1,000,000 Award Tickets were canceled or changed within 72 hours of departure. As a result, almost all of these seats departed empty as other members did not have enough time to book them.
In an effort to make these seats available to others and to improve Award Travel availability, we need to implement a policy change. Effective ...