Bethesda had announced at their E3 press conference that they will be getting in on all the VR hype that is going around. The publisher will be integrating Fallout 4 and Doom to be able to use VR.
Bethesda’s Pete Hines announced that Fallout 4 will release for the HTC Vive in 2017. No platform or release date was mentioned for Doom yet. However it is likely that it will also release on the HTC Vive as well.
The HTC Vive is the highest priced VR of all the choices out there, so it seems it will have the lowest of the markets share. This makes Bethesda choosing it for Fallout 4 kind of interesting, unless they think maybe their game will help push the HTC Vive into homes.
There is also the possibility that not releasing game on Oculus is due to the ongoing lawsuit between Zenimax and Facebook over John Carmack. Although that has been going on for two years now, it may still be the reason for Fallout 4 and Doom not coming to Oculus.
Source: Gamasutra