I can't comment on the book as I don't know which one it is, however to put your mind at ease, here's a quick muscle growth 101. With usual resistance training the eccentric portion of the movement causes microtrauma to the fibre (as long as sufficient resistence is used to create the necessary tension. The body will respond to this by remodelling the fibre to become thicker and therefore more resistent to damage in the future.
This requires protein, and if it is not supplied by the diet, the body will canabolise other tissue to provide it. So protein in the diet (whether from whole food or supplementation) is needed to prevent a catabolic state from occuring, and promoting an anabolic state (a least from a protein metabolism standpoint). This remodelling is called hypertrophy and is the primary way muscle growth occurs.
However there are at least two other ways muscles can grow. One way is for the muscle fibre to split and form a double (once it reaches a certain size limit), which allows each seperate fibre to hypertrophy once more. The other way, as you mentioned in your post, is to recruit satellite cells. These are both termed hyperplasia, the former will happen with regular weight training, the latter requires a more traumatic stimulus.
This could be via unintentional injury or intentional damage using very high tension levels such as those created using heavy eccentric stresses, especially in the form of negatives. Using methods such as negatives activate satellite cells into growth of new muscle fibres. This supply of satellite cells is limited however, although researchers have not come to a definate conclusion on how much, estimates are approximately 10%.
As far as metabolism is concerned hyperplasia like hypertrophy requires protein in order to occur. So the bottom line is in order to support muscle growth, higher levels of protein are required and supplements are a convenient and efficient way to achieve this especially in the peri-workout timeframe.