just a sharing from a friend, in the summer time (June or July? not quite remember that) he and his gf had a booking on reward F with AM on CX 542 to HND xHKG. When they checked in, was told that there's a equipment changed and no F will be on that flight. Downgraded with only miles differences given back. Since both of them are owe so F lounges will be a must for them. However, the weirdest part is that when they reached the gate, a 744 as scheduled is parked. With their updated J bp, they asked the staff at gate to get their F back, and a negative answer is given. So the entire flight they spent their four hours on the coffin seat looking at their originally booked F left empty there.