A lot of content had to be cut from the final game due to difficulty, redundancy, lore changes, and various other reasons. The Original ODAS 1 would have featured a whopping 12 animatronics. Two of these animatronics can still be found in game on cam 7, Those being Old Birb and Old Snurb. But don't worry, i'm sure they will show up again sometime in another game ;)

The Original OWAD Office lacked a window and instead featured a large door for Tibby to appear in. Powl would ender through the side vents, Kobe and Alex would use an exposure bar simular to the one at flumpty's, and Seed would need to be calmed with music instead of being shaken off of his plant. On top of this, seed would be behind you, requiring you to turn around to deal with him.

The original ODAS Office lacked the urinal and looked a little bit different, featuring a window to your right rather than a door, as well as having the desk up against the wall with a full monitor on it. Notibly there is also a light switch, this was intended to be used for a scrapped mechanic involving Pampkin. The player would have to shut off the lights if they saw Pampkin outside the window or he would break in and jumpscare them. Rather than having the door shut, keeping the lights off for too long would raise Jeffso's anger meter. 

While Terror Night isn't officially scrapped, the chances of it coming out are pretty low. Initially there was supposed to be a second, harder night of Snurb's Hotel where all the characters were swapped out with Terror versions with more unique mechanics. If the idea does ever come into fruition it would most likely be in a remake or in one of the later games.