Forces Fanatic here, It was there, Holding the crouch/slide/stomp button on rails makes you crouch, But even I noticed it didn't do jack diddle, It was there to be there I guess. I enjoy not having to balance on rails, As it hurts to get used to and makes performing hop-offs harder, I'd enjoy it if leaning did come back, Just not required to stay on the rail, Like leaning makes you go faster depending on the curve and what direction you're leaning.