Could be, but Corning states some facts that may be true. Apple also has a big investment in sapphire. It also of late has had some premature releases. may screw up again.
A big change like sapphire with zero track record in the worldwide market is a very huge risk for Apple.
It has been used in high-end watch faces for decades.
Other commonplace uses of sapphire in everyday life include semiconductors and barcode sensors, where the material is again chosen due to its ruggedness.
Sapphire has also found widespread use in is the avionics world, where its ability to withstand extreme high and low temperatures — along with its resistance to damage — makes it a useful tool for the aviation displays in aircraft. Another regular application is in the optic heads of missiles. These missiles are regularly equipped with a combination of infrared, radar, and optical sensors for guidance, and the optic heads need to remain undamaged when the missile is moving through the air, or else being handled on the ground. Sapphire is also used in some iterations of bullet proof glass.