dnd 3.5e – Why are the rules of the polymorphic sub-school of magic separated from the rest of the book?

When I bought the basic rules book for the first time Dungeons and Dragons 3.5, I took a quick look at all the books. One thing that struck me was the fact that everything at the back of the Player's manualhe showed the rules of the Polymorph Subschool. It seemed odd to me that it was at the bottom, behind all the clues and so on, on the very last page.

Why was this done? It gives me the impression that this decision was made after the fact, but it would make no sense for a company like Wizards of the Coast to do that. Why was not it included at the end of the magic section?