According to The Detroit News, Ford's product chief, Raj Nair, stated in an interview that the vetting process is to ensure the GTs go to valued, long-standing Ford customers that likely won't sell the car for profit or place the car in a collection for viewing purposes only. The company wants owners of the new GT to enjoy--and by enjoy they mean drive-- the car as an automobile is meant to be enjoyed.
The application process includes a section stating the potential owner is prohibited to sell the car for a certain (but currently unspecified) length of time. The purpose of the process is for Ford executives to gauge the applicant's relationship with the brand. They want only true Ford enthusiasts-- rather than just car enthusiasts-- with the new GT in their possession.
The application process is scheduled to go live sometime this month.