Interesting, I hadn't read that part of the CA yet. As for rotating into the turn, there are two schools of thought there. But first of all, I don't think this advice applies to toeside turns. Rotating the upper body into the turn on toeside (clockwise for a regular-footer, viewed from above) is very old technique that often leads to bending over at the waist.
Back to the two schools of heelside technique. Some people like to face their upper body towards the nose of the board, which is the same thing as saying "leading the board by about 30 degrees". Some like to face their binding angles. The difference is whichever works for you. They are both fine techniques.
However for newbies, it is often necessary to tell them to face the nose because they're facing the toeside edge and they don't realize it. Facing the edge is bad and leads to the dreaded "toilet-sit". By trying to face the nose, they may end up facing their bindings, which is fine. <b>Often you have to tell people to overshoot the target in order for them to hit the target.</b>
This may be their rationale when saying look uphill - maybe they're just trying to break the bad habit of looking straight down the fall line. Nobody actually looks <i>uphill</i> during a carve, maybe just once to check for traffic.
Now, on toeside, I am a fan of facing the nose. IMO, facing the bindings makes it harder to do the hip-drop, harder to angulate, and easier to bend over at the waist like this.
Many people face their binding angles on toeside and do fine. I just think that for a newbie it is too easy to develop bad habits doing it. If you want to try a little drill to make yourself face the nose, try grabbing your rear boot cuff with your front hand as you make a toeside carve. Whenever I feel my toesides getting sloppy, I do this and I get that nice hip-drop pencil-pinching feeling back and the carves feel good again.
-Jack