As it turns out that might not have been the case, at least according to a post on Daring Fireball by John Gruber, a well-known and well-connected Apple insider. According to Gruber, it seems that Apple had decided at least a year ago that the iPhone X would feature Face ID as its main security feature.
The report claims that Apple did try to embed a Touch ID sensor into the display, but apparently that was actually Plan B. It seems that Apple was convinced pretty early on that Face ID was the way to go. This was apparently “confirmed” by several sources at Apple, including engineers who worked on the iPhone X.
Some of the rumors were right in the sense that Apple never got Touch ID to work on the iPhone X, but it was because they did not pursue it and abandoned the idea early on, as opposed to technological hurdles. In any case take it with a grain of salt, but it is clear that Face ID is the way of the future for Apple products. Whether or not it will work as intended remains to be seen, but we’ll have to wait until November to find out for ourselves.