Comapred to the Emepror, yeah, I'll agree that he was more effective as a villain. I think BW:A tried to go with the whole mystery man archetype for the Emperor as a protagonist, and it wound up not working because we simply didn't care two credits about him or what he was trying to do.
Plus Malgus was a poster boy for the Sith, so in the advertising build up to launch, you kind of wanted to know more about him then the Emperor.
Wait, really? That's the best news I've heard all week o.O
It was almost the second established thing since Disney purchased Lucasfilm into their corporate portfolio besides stating they would be hands off with the project like they are in large part with Marvel and that the story would be based on old story notes written by George and that he would still retain a role in the movie as chief creative consultant. The story would be set with Luke in his later years (the "proto-script" written by George Lucas states his 40s) training a new generation of Jedi.
Luke in his 40s places the timeline of these new films to be around the, you guessed it, period of the New Jedi Order series and thus the YuZhanVong would be cut from continuity entirely.