kyogen: No, the scene from the trailer is still there. It's a matter of which path through the dungeons you choose. I missed it my first time through as well.
AudreyWinter: Hm... I was actually in a torture chamber and killed two guys, but there was nobody else. And I've also seen that crack in the wall I've seen in the trailer, but there was nothing behind it. And I ran through that dungeon back and forth many times, no trap door. And would it be too much of a spoiler to say what the 4th way is?
Spoilers for Prologue
The 4 ways the Prologue can play out depend on two things... Your interaction with Aryan La Vallette, and the path you take through the dungeons. If Aryan survives your first encounter, you then encounter him in the dungeons. If he doesn't survive, it's his mother you encounter. Depending on the path you take through the dungeons, you encounter them in different circumstances... if you take the 'high' path, you come across them being led out of the torture chamber, and if you take the lower route, through the hatch, you encounter them in the torture chamber, and fight the executioner. Even if you take the high route, you have to fight the Executioner I think, to get a key. So, the 4 ways are two encountering and escaping with Aryan, and two with his mother, one each when they are being tortured, and one when they're being led out.