I honestly don't understand why people keep wanting to see the adventure we essentially play through in another medium. If they're making a Pokemon Light Novel, I want them to explore other aspects of the Pokemon world or go into the lives of other NPC's.
This. So much.
Not only it would be bad to standardise all protagonists, their starters, actions and side-quests during their adventure and all of these [outside an actual game too], but also the chances of it staying completely true to the games' plot are just too low.
To date, there's not a SINGLE Pokemon manga, anime or light novel definately set on the Pokemon Main Series universe. Most are based upon the games up to a point of following the basic line of plot (Special, Anime, DPA, to name a few popular ones), while others simply screw on keeping several aspects of the Pokemon world true, although not directly based on the games (Pokemon talking, and other stuff on Magical Pokemon Journey). How I became a Pokemon Card seems to be very faithful with lack of contradictions, and from what I've seen, it may be considered to be taking place on the games' universe. I'm not sure about Pokemon 7 and Getto Daze, but Team Galaxy in former and In-Com in latter, lower the chances.
A light novel set on the Main Pokemon canon would be completely awesome. A different cast with different targets could well be featured, and cameos and references would give it great eyecandy. 
But most Pokemon media exist to solely promote the said respetive games they're based on, so, I don't see anything like this on direct future...
