Wouldn't they get similar data every year?
Its just more obvious this year because the price of the X is higher than previous iPhones.
There's a reason Apple always sold "last year's iPhone" at $100 off the previous price instead of dropping it, and this time around even sells "last year's +1 iPhone" at $200 off the previous price, and a reason the value of a used iPhone holds up better than that of other phones.
Not everyone wants to pay full fare for a new one, so Apple offers options to pay less to get a cheaper one that's new but not the latest n greatest, which a lot of people take advantage of. Some people don't even want to pay that much, which is why there's a thriving market for used iPhones.
Adding a $999 option obviously increases the number of people who will say "that's too much for me" as that was nearly a 50% rise from the standard entry price for the latest (non plus sized) model. That's probably why the rumors say they will be offering a less expensive one that skips the OLED screen next fall, so people who don't want to pay extra to get one with OLED don't have to. (Fortunately the other thing that made it cost more, terrible yield on the 3D sensors, has been fixed so that won't be a major cost contributor for future Face ID models)