"The Grand Admiral was smart and subtle, but never used his brilliance to show up or humiliate anyone.
He demanded results, but never perfection, and had amazing stores of patience for those who were truly working to their fullest ability.
It was a pity Thrawn's style of leadership hadn't spread through the rest of the navy.
If that happened, he suspected, the Empire would stand forever."
I really hope your right. Problem is that can only happen if they film new material.
I have no doubt Maul would have been featured in Season 6, so some Maul stuff should be available for the Bonus material. But I have a feeling they were not planning on finishing his arc until the planned Seasons 7 or 8.
Which would mean they would either have to film new stuff or not show Maul at all in the bonus material, leaving us to assume Sidious lied and actually did kill him.