I've given this some thought.
Zuck is never going to get his 2billion back via Oculus directly. Its only ever going to be indirect, via services thst use VR, any VR.
The Rift is hardware, and while posible (but highly unlikely) to have facebook data slurping firmware that data has to be collected via its driver. The will be open source drivers.
Zuck is not going to be getting much usable data from me playing HL2 with an oculus, or from any of the first or second gen VR software.
Its the generations after that he's got his eyes on. The software that majority of people might use VR for, virtual shoping, movies and events.
If you don't want to feed zuck, then don't use those services.
The money and resources Oculus have just got are good for VR, the unpleasent VR facebook stuff was going to happen anyway. The only real change is the Rift will come sooner and better.