SOCs can be bought and reverse engineered through physical methods. Having the schematics is just cheaper from a time perspective but is easier to catch and has greater legal risk. If Intel could reverse engineer designs, how about AMD, Apple, Qualcomm, Huawei, Samsung, Texas Instruments, IBM, MediaTek, etc? What would be the point if you can get caught either way? Intel isn't like AMD, they don't have a history of reverse engineering their client's CPUs and selling them as their own designs. Stop projecting.
Chopping off their vertical integration isn't going to do anything new, it is just a different business model that many have chosen in the past. Having control of both their own design and fabs give them better feedback on how changes on one affects the other which can lead to more innovation.