One of the main features of Big Bang is an improved experience curve. With anywhere from 2 to 5 times faster, 2x EXP coupons are no longer an essential part of the leveling experience and so we will remove the coupons from the Cash Shop with Big Bang.
Maplers who still have 2x EXP coupons in their inventory will be refunded the remaining time with Maple Points. Please give us a few hours after the game is live tomorrow to complete the refund. 2x Drop coupons are not affected by this change.