I'm not usually one for theories or any of that sort but something really stuck out in this teaser to me that nobody has really picked up on yet. We all know that Antonette is made of what looks to be metal, and is in NO way black with white stripes going down the arms. Keep in mind that the marionette was never in a jolly game- The way the arms are positioned above the other animatronics makes it look as if the puppet is controlling these animatronics, perhaps for a deeper purpose. At the end of jolly 3 chapter 2 we saw the suit of springtrap laying lifeless on the ground, this suit we can presume is one of the things the person you play as (theo?) was looking for. Maybe the soul who possesses the puppet possesses antonette to stop William afton from striking again by locking him deep underground. As stated in jolly 3 chapter 1 antonette (and the others) just want to be left alone so nothing bad will happen again, and maybe this is why the animatronics keep attacking you. You broke a rule. You are "rewriting history" by going into the building and possibly awakening the soul of the dead William Afton. As a final way to deter you from this path, antonette finds a way to make the building collapse, trapping you and William Afton inside, but your only way out is through the "Good time" animatronics.

Yknow what... this is a fairly decent theory.

I might build on this.

(Edit antonette's name is Tal)