Sorry for the bump, but thought it worth mentioning ‘Prince Xizor is Canon Again!’:
https://www.youtube.com/watch?v=C_b0DUoydxY - a short video from Star Wars Explained
He was mentioned in the recent Crimson Reign comic by Charles Soule.
At this point they may as well make ‘Legends’ the old EU again! More Black Sun is very welcome too.