x is their premium offering this time around so they would probably want to keep the pricing tight at launch. i believe iPhone 7 was the first time iphone had cashback at launch. otherwise they have been pretty strict about discounts on their latest gen phones. iphone 8 is already being skipped by a lot of people planning to get the x this time around. same trend globally as reports claim that they have lowered production of the base model because of lack of sale. though i guess they might attract more customers to x if the cashback is significant enough to put it close to the top end iphone 8 plus. god knows.