Unlike in previous cycles, there's 3 models to choose from this time around - the expensive showcase, the established flagship and the larger variant of the established flagship. There are valid reasons to opt for the 8 or 8+ instead of the X, even outside the price.
The last concrete(ish) figure we heard was 29 million, which was lower than consensus expectations of 32-35 million, but not bad for a device which is priced extremely uncompetitively. I do think this will spur Apple to drop the price of the XI, however, with the XI+ taking the 999 price point and the XI starting at between 849 and 899.