Disney declared almost all of the EU (comics and books) as no longer canon, so now it's only the movies and the two shows that have been out recently in Disney XD and Cartoon Network. This was to give the writers more "creative control." While they said some characters and stories MAY find their way into the new canon, it's hard to imagine that characters and races like this would be able to find a new place given how undeveloped they are. However some people have said that only post ROTJ EU was declared uncanon while others are saying all of it is, it really sucks :-/