Apparently, and this isn't confirmed but highly likely. The reason Sony doesn't have a fully featured RDNA 2 GPU is because instead of waiting for AMD to finish they took what was available, and then kind of went their own way building the remainder of the feature sets themselves under proprietary methods.
This allowed them to get their devkits out sooner, their tools, developers to get more in tune and comfortable with developing for it. On the Microsoft side it appears they waited until AMD's hardware was entirely done, which like the opposite of Sony explains the reported late arrival of devkits, spec targeted PC's being used and as you can see now software which appears to be having some issues.