Using PS4 Share to broadcast "Until Dawn"? The publisher has disabled archiving for this game. We're reaching out to hopefully enable. ^JM

— Twitch Support (@TwitchSupport) August 26, 2015

No official comment from Sony on reasons why they took this action, only speculation.

On the other hand, Game Informer says it could have something to do with streams through the PS4 Twitch app, as they broadcasted Until Dawn through completion and their stream remains:

http://www.gameinformer.com/b/news/archive/2015/08/26/sony-disabling-until-dawn-twitch-stream-archives-coming-from-playstation-4.aspx

smart move sony.. smart move. apparently marketing your game for free isnt something you want.

More like they don't want people to watch start to finish runs through the game because they think such people might not buy. It's not like they're preventing people from live streaming, which is the actual bit the promotes the game.

Well Twitch is spoiling the game and by allowing the community to view the game will decease sales. Yes its a shock to those who think Sony aren't in it for the money, but they are, they really are. Nintendo would also do the same thing just like Youtube.

Game plays like a very cinematic experience, I can see why they would allow live streams of it, but not an upload of the game start to finish to be left up there.

Tis sort of like saying film studios should put their full movies up on youtube to watch to market it to more people.... I mean, more people would see them yes but if it hurts the bank balance it shouldn't really happen.

I find it unlikely that someone would watch a game from start to finish instead of buying it and playing themselves. It looks like a crappy B-horror movie to be honest, but playing it and making decicions yourself, that should be an entertaining experience.

yeah i thought it was ALL live streams of Until dawn. however, i think if somebody is willing to watch an 8 hour game from start to finish, i dont think they were willing to buy it in the first place. 

With this type of game, I can see why. It's basically graphics and story. Compelling but not exactly fun to play. Don't give away the good stuff for free!

Aye quite true as well, I never really understood watching lets plays myself, if I have the time to play a game... I'll want to be holding the controller, not some popcorn trying to hear the dialogue over fake reactions from the uploader to be "funny"

Unless they are worried about spoilers I don't see why they would or should do this.