Disney has been very public about it's distaste for the EU and the overall direction that LucasFilm allowed it's property to be developed. It is frankly hard to explore new and exciting stories if you have to constantly check every single detail against hundreds of books and comics. Readdressing the EU is one of the smartest moves Disney could have made. Disney has also been very diligent about removing references to the EU in their merchandise, take this for instance. We know that is an E-Wing but Lego has branded it a prequel "Stealth Fighter." That is a brilliant side step. Also, look at the other stuff FFG has been doing with their stint with the Star Wars IP; they completely changed the RPG and made it all about the Rebellion. WotC was all over the place when they had the RPG.
Why do we get the E-Wing, Headhunter, Defender and Phantom? The Defender/Phantom make a bit of sense, they were both in classic LucasArt games and we already know that Disney doesn't mind referencing games the classic games as seen with the HWK. The E-Wing and Headhunter are much more puzzling to me. Maybe they were in production prior to the EU crackdown earlier this year, or maybe Disney just doesn't mind what they throw into this game to keep it going until EP. 7 comes out and we have a whole slew of new ships. It's anyones guess.