Cragley hit it on the head - according to any FF
program, trips that are pending from FF
miles would be honored, but they can drop the program with about 6 months notice.
Let's use Delta in this case...Sure, they'll be some
customers who would defect to another carrier in protest, but when push comes to shove, if Delta has a flight that A) fits the schedule and B) is priced right, most folks will book that flight. Because the fact is, most "elites" are not buying their tickets - their company is. And I don't know of many companies who would accept "I will not fly Delta because they don't have a FF
program" and gladly reimburse an employee for paying more and flying on a less convenient AA
or UAL flight.
An "employee friendly" company might
agree to reimburse them for the cost of the "company preferred" flight and let the employee pay the difference out of his/her own pocket for the flight on an airline that does offer a FF
program - and only if the schedule of the "employee preferred" flight was within an hour of the "company preferred" flight. My guess is that folks who try that will find themselves less willing to pay
to go to work, and they'll fly whatever the company tells them to fly.