Yeah that seems highly unlikely then...so most likely it is all about VR and 4k movie playback.
I've said this so many times already, in other forum debates too.
The biggest market share for VR is, and for the foreseeable future will be, 360° video. Youtube already has Snoop Dog involved in promoting it. It's where VR will thrive outside of gaming.
The PS4k is not going to be powerful enough to render games in 4k. Upscale perhaps, but I firmly believe that this is simply to add enough ooomph to play 360° videos in 4k. If it does make regular ps4 games look better, the die hards will be miffed, but they are not entitled to be.
I'll be miffed as well if I can't afford one straight off the bat, but that's my problem!