One thing to realize is that Notch really never had any plans of making a VR port of Minecraft. In the past, he has stated that because of the JAVA technology used in Minecraft, it was too difficult to do it right, and they were having a problem making the UI work. They weren't very thrilled with the way the Minecrift mod did it, and wanted to do it better, but it just wasn't possible.
(In fact, the Minecrift mod doesn't even work with anything higher than 1.6, which means you can only use it in singleplayer or on servers that never upgraded. This is because of how much things have changed in the code between 1.6 and 1.7.)
So, Notch actually abandoned the effort sometime last year.
Last year: "We aren't making a Rift port because it's just too difficult with our current codebase."
Yesterday: "We aren't making a Rift port because Facebook."
To me, it sounds like a convenient excuse to cover up the fact that their codebase is really messy and can't do as much as they wish it could. We can blame it on Zuck now!