Although if they do follow EU, they'll gain that audience and get the potential praise and approval of the fans. I'm hoping they see it this way, at least. I would expect they'd have someone like Leland Chee giving advice during the writing of the movie, and he's well aware of the EU events.
The audience of the EU is really really small compared to the whole Star Wars audience. Like less then 1%.
The Thrawn trilogy is a great book probably the best of the whole EU BUT it would make a horrible movie. It's not very cinimatic, a lot happens in it, and there is way too many scenes where they are just talking to get across major plot points.
If they made it into the movie it would either be really boring or leave out a LOT of stuff.
It would be better for a HBO series.