I personally felt the story behind FNaF had no business being in a video game. If Scott were to write/produce a webseries that retells the plot of the trilogy as he interpretted it that would be really interesting. That said, I don't think he would since I feel he really likes how fans debate endlessly over the back story. I also think a book might work better for the story as well because a lot of the implied violence and themes could be really well done if written by someone who was a talented writer, but I wouldn't bother buying a book that wasn't at least co-authored by Scott. Still very curious as to what the "real" explanation is behind the various events of the games, reading all the theories has been interesting but I am at the point where I would rather get straight info from Scott now instead of the endless speculation.
The mental image of what happened to Spring-Trap still gives me shivers and I cannot think of any other game that has given me this sort of creepy feeling.
As for this specific video, I'll watch it when it comes out because I like animation in general and it appears to be very well animated but as far as it being at all FNaF related, the trailer doesn't instill any hope of that. If it were people in suits attacking people it could be interesting but the trailer shows animatronics covered in blades and spikes battling special forces looking people so I doubt it will be of any value to my interests in FNaF. Still would watch it though because I like smooth animation, even though this looks more like some sort of well made fan-fic than any sort of attempt trying to expand the universe (which would still be fan-fic but I mean focused within the established source material.)