Originally Posted by
cringle
there would be a change fee involved (you don't indicate whether you're booked in main cabin or MCS, so i'm assuming main cabin). true, you paid an upgrade fee, but since you've originally paid a main cabin fare, those fare rules would apply to the flight change. the upgrade fee you paid, doesn't earn you COMPLETE first class benefits (only the on-board ones).
Just did exactly this today, and cringle is right -- booked in Main Cabin, upgraded to First within 24 hours, then changed the flight and had to pay the $75 change fee. So any loophole that ever existed seems to have been closed. The rules of your original fare, not the upgraded fare, apply.