Or maybe Ford decided its more profitable to move out of states that aren't right-to-work?
I work and have worked at several Fortune 500 companies as an individual contributor, supervisor and manager. The numbers at all of them indicate Union facilities cost at least 10-15% more to operate (not including wages). My current and past experience is its probably closer to 25% when you add in wages and having to deal with some of the nonsense that can come with Union, particularly UAW, facilities.