I think it would be advantageous for Sony because it would increase the headset's value and more people would buy their peripheral.
Just like it was advantageous for them to put a standard USB HID interface in the Dualshock 4, so that people buying it won't think "this is only for the PS4 and then it's useless". Each DS4 can be used for "eternity" even when the PS4 is long gone.
Same thing for PSVR. "When the PS4 is gone, I can still use it with a PC" and that would be great.
The only problem I see with PSVR becoming available for PC is the fact that it uses the Playstation Camera for translational movements, which has dual optical sensors for depth perception so it would be hard to replace.
I heard somewhere that the PSVR is only using one of the sensors so it could be replaced by a regular webcam, though that might be a long shot.
Though the camera connection is probably just USB 2.0 using a different connector, so if someone made drivers for it I guess a cheap USB adapter could be sold. And then they could sell even more PS Cameras.
On the ps4 the psvr is the best solution for VR. On the PC it would at best be the third best.
Third best for 250€ less than the price of Rift. And many people consider it on par with it.
Plus, it's available on retailers everywhere under a globally recognized brand, which is the second largest reason why its total sales surpassed the sum of the other two within a month after release. Both Oculus and HTC screwed up badly on distribution.
Then what about software ? Valve has steam and Oculus has Oculus home. Both have exclusive software to the stores and with oculus exclusive to the headset. Sony would be entering with no store and no exclusives.
Steam VR isn't exclusive to Vive. There are 3rd party headsets that are compatible with Steam VR already. All they had to do is provide compatibility with Steam VR's platform like all the other headsets.
All those incoming $300 headsets that have been teased by Microsoft are most probably coming with support for SteamVR.
So they would be selling a $500 steam vr headset that doesn't have light houses of the touch wands.
The PSVR is $400/400€. That's
1/3rd the cost of the Vive in Euroland at the moment.
The only place where the Vive isn't prohibitive is the US, and even then it's still 2x more expensive.