If the Warcraft Movie Rewards is true that proves that Legion will not be released around the time the movie comes out.
Many people keep saying it will release before or near it and many times I have stated no it won't. The reason why it won't release before or near it is because the sells of one product will overlap the other. This isn't anything new all companys (Gaming companys anyway) do this.
Any time they release two products near each other the sells of one hurts the other.
To add the Movie Rewards gives all current expansions and one month game time. This is to get people interested in the game and maybe become buyers of Legion.
There is no way they would give this out then go "hey guys go spend another $50 to play the most current content". If they did they it would be a massive turn off for people.
So like I said before the best release date we can get is late July. If this is true its really smart marketing by blizzard.
Thats my 2cents so what is yours.