First off the demo update news comes from residentevil.com.br, who got the news from residentevil.com.fr. So it might have just been a misinformed PR rep. Though we all know a update is coming at some point. They also mention that the length from said rep is said to be about 15 hours. Though we know replayability is planned due to the game having multiple endings, and actions in the game changing how things can play out. Also mention that VR players might take longer with the game. I'm assuming due to being in a VR environment, you'll want to explore more I guess. Also the demo is still planned to hit Xbox One and PC at some point.
If you were somewhat disappointed with the updated demo of Resident Evil 7, just wait a little longer. According to a representative of Capcom France, Beginning Hour demo will be updated again in January 2017, probably just before the release of Resident Evil 7.
Again, Capcom said that the demo will come to Xbox One and PC, but not confirmed any date yet.
The information is the partner site ResidentEvil.fr (UltimateRE old) who had the opportunity to attend a conference on the game during an event in France.
In addition to confirming the update of the demo, Capcom released information on the total duration of the game. Resident Evil 7 should last on average 15h to be finalized, but the time may be much greater for those who are playing in VR (between 25 and 30 hours ).
Three DLCs are already planned for Resident Evil 7, which add about 8 hours of gameplay.
Resident Evil 7 will be released on January 24, 2017 for Xbox One, PC and PlayStation 4, with support for PlayStation VR.
Xbox Preorder News
Now aside from all of that Xbox One Digital preorders have opened up as well. Both the regular and deluxe (comes with season pass), offer the preorder bonus Survival Pack recovery set. Which are some extra items I believe that can be used in either the normal or bonus difficulty which is part of the preorder bonus (That bonus difficulty can also be unlocked by completing the game once).