I don't think anyone has mentioned this so far, judging how you're all still gnawing at the idea of wether the camera might be fixed at certain points in levels
I noticed in the GDC 2014 Gameplay trailer on the NnT oddworld.com page, that at 1:18 in the video where Abe moves through the broken down ventilation tunnel: the camera sticks to the edge until he reaches the end of the tunnel.
I imagine that's how they're going to do it for secret areas aswell, including having objects concealing the entrances to secret areas like in AO and AE