So there's separate books. The guide book and the alolan pokedex books are 2 different things. But they do show pokedex off alola in guide book just not in detail

So in sun and moon guide. Each page contains 32 Pokemon. So it takes up roughly 9.5 - 10 pages.

So even if they put the whole fucking 820 Pokemon. (Which they won't) it's only gonna take up a 16 pages more but USM book is 130 pages more.

So definitely a lot of new features in the games