With the Pantheon restored to some degree, can't the Titans help the Orcs and even the Draenei rebuild their homeworlds? We've already seen a glimpse of Draenor in WoD and how Outlands can look.
In the new cinematic we see Saurfang tell Thrall that Outlands is beautiful, but it's dying. But is it an inevitable fate? The Titans are powerful enough to modify and shape planets. Can they be asked to assist and help mortals in rebuilding their broken worlds? They do owe the mortals of Azeroth for helping them imprison Sargares.
By restoring Outlands and reshaping Draenor Blizzard can unlock alot of potential in the Warcraft universe. Perhaps WoD's alternate Draenor can be used as a blueprint by the Titans similar to how the emerald dream was used as a blueprint for Azeroth. This can also serve as a great expansion idea as heroes help the Titans restore the broken world, travel into the twisting nether to retrieve important shards and items that were lost when Ner'zhul's portals ripped the planet apart, defeat void invaders and other threats and finally restoring an entire planet to it's glory. It can also be a great excuse to revisit Outlands and explore the lore of the zone further. We have so many mysteries that are still unexplained, The old god that the Arakkoa worship for instance can be explored further. The Ethereals can be confronted and stopped from exploiting Outlands further.