Delayed post but I called in on March 1st to change some tickets from YYZ-GCM and had no difficulty with the exception of paying the $90 per ticket change fee which I knew I would have to in advance. I spend the extra 3k and upgraded to J class fro Y.

Also, had no problem securing 4 J seats to CUN the end of June for my annual summer vacation.

So far so good for me.