UPDATE - Me and lancer had a quick look round the new area and found that it leads to the Templar area, missing out the vanishing rocks, and gives you a vantage point which one person even claims to have soloed the Templar this way. I'm hoping this new area is meant for more than just a bypass and a vantage point, and am keen to search for a chest here next time we raid. If you read the recent comments for the third video I linked, one guy has an idea where a chest might spawn in this new area: "There's a possible chest spawn point I found as well. At the bridge you crossed at 1:48-1:52, put your back to the wall while standing on the bridge and you'll see a small tunnel straight ahead of you (across the drop area). If you enter it, it's only a few feet deep, but if you look up from there, you'll see footings you can scale the wall with to come into another short hall that leads to a dead end. That's where I think the chest will spawn in this area." Someone claimed that when they did it on hard and no one died, with none of the plates ever being taken, that a chest spawned. Another that there's a door that they couldn't open. Others also say it's just an alternate route, but here's hoping.