This appears to be a very cunning sales strategy by Ford.
I am sure The guy responsible for sales and marketing of the Mustang is catching grief that sales are behind the Camaro.
This is a great way to get potential buyers off the fence to make their mover earlier than later
The only reason to reveal a design 2-years early is as a tool to spur sales of the outgoing model.
Most Mustang fans while be desperate to get the current design (while they can) instead of having to settle for another soap bar to long in the shower design