This is so funny (and sad, for your consumption of time). Obviously, somebody has told a mass of call center employees that these certificates must be surrendered. But, any time I've heard of someone going to the airport with these, the ticket counter people have no clue what they are. So, in the end, they talk on the phone to their own staff, keep the certificates, and then throw them away.
I have not heard of anyone losing their reservations because of the certs not being received. How would they know?