Hmm, doesn't make much sense really....
Unoptimized games will run better on the system with more raw horsepower. Games will run better by brute force.
PCs will be the lead platform and what we should expect the game to look like (Original quality developers intended) while the consoles will try to replicate this quality as best as they can... Are you suggesting Xbox One is more capable of replicating the PC then PS4 despite the PS4 having more horsepower and being easier to program... or are you just setting up a backdoor to run out in case you're wrong about the power difference?
I'm saying it depends entirely on development schedules, priorities etc. For example, a few games have been shown off on the Xbox One more than the PS4 and vice versa, likely due to marketing deals. In these instances, because demo versions of the said games have had to have been prettied and polished for public showcase on these certain platforms, I'd imagine those platforms will have had more emphasis and tender loving care at this early stage. At a point where neither has had nearly the amount of time and optimisation ideally required, and that will be quicker to do and more efficient going forward.
It's not even a back door, developers themselves have said as much.
HipHop Gamer interview with Geomerics (Enlighten/BF4) developer Pt 2/3 (PS4/XO)
Notice two of the points he brings up as mentioned in my summary...
- You won't really start to see differences between the PS4 and Xbox One till later on
- As it will take time for people to extract more from the hardware of both