Originally Posted by
jiejie
Don't make the assumption that if the PEK-BKK flight is delayed, that they will also change the normal check-in cut-off time in a way that benefits you. Doesn't usually happen that way. I've tried this gambit on this very same flight with CA and the original cut-off for check in remains in force even if there is a delay. Understand that they may load the plane, shut the door, and push back from the gate then sit on the tarmac for the delayed period.
At least with MU (which I fly the most often), the current SOP is to send SMS/Wechat notification about delays (when possible) to formally acknowledge the new departure time (and other times that are tied to it). I kind of like this system because it has already spared me of a great deal of wasted airport time.