Originally Posted by Bokken
link will explain it a bit better; if it comes directly from Lucas, it's considered written in stone. If one book mentioned the recovery and disintegration of Maul's body, for example, it would now have to be retconned because this new development comes from the highest level.
My point is that it's no different from the EU bringing back Boba from the dead. Both are canon. Then again, Lucas could change it back if he wants, but it's a bit hypocritical to support Boba's return and rant over Maul's. We don't even know how he returns. I'll wait and see before I judge.