Najo, I like your optimism but I don't share it. What I like about WHFB is that it is a generic fantasy world, where I can carve my own little empire if I want, or hitch my wagon to some already established background.
But you CAN'T just "carve out your own little empire" at the moment, because the fluff is so fixed and stagnant and there really isn't any room for expansion. The borders are defined, and if you want to change them you must rewrite the fluff.
...which is of course an option, but it's an option whatever direction things go with 9th. You can write your own world. Play WHFB in the old one world or the new.
Changing that world fundamentally, changes my motivation to carve out my own empire. As an old Bretonnian player, I would have zero interest in re-starting a Bretonnian army that is simply a facet of the Empire army. Likewise I would have zero interest in starting a Dwarf army that is an add-on of the Empire army, especially if Sigmar or Karl Franz became a 'good' Chaos power and became the go-to power-house units to combat Chaos. My motivation to play a Vampire army only comes from the fact that I go through considerable mental acrobatics to maintain my own vision of Sylvania and the Old World in general.
I anticipate that Sylvannia will be shorn off as one giant chunk, protected by the will of Nagash. It's been strongly foreshadowed in the fluff, as **SPOILERS** Nagash bound the essence of the wind of Death to the land of Sylvannia itself.
What I want to see from 9th is the current setting +200 years, where all the old factions return to their old haunts and rebuild their old empires, maintaining the generic feeling of the world. I want them to reset the clock without fundamentally changing the way the armies work or feel, and without changing my ability to create my own little kingdom.
Booooooooooooooooooooooooooooooooooooooooooring.
The Warhammer world is boring, bland, and generic. It's been exactly the same for thirty years. The same damned characters fighting the same damned battles, with Chaos always on the brink of destroying everything but never getting further than Middenheim without a retcon or orc headbutt pushing them back.
"Building your own narrative" has ALWAYS been core to the philosophy of GW's games. However WHFB is hamstrung by their stagnant world with its defined borders and lack of mystery. Bretonnia can only expand by conquering parts of the Empire or Tilea/Estonia. You need to go through mental gymnastics to justify why Tomb Kings and Lizardmen are fighting a campaign against each other, and on that medieval city board nonetheless.
When GW progresses the storyline I will 100% guarantee you that it's to appeal to exactly your type of player. The sort of person who wants to make their own mark on the world, and forge their own narratives. They'll just come up with a reason why any army could be fighting any other army on any terrain type...just like they do in WH40K.
EXAMPLE: The Empire cities of Hochmarch and New Middenheim were founded on a large planar shard, comprised of rolling fields and a few ore-rich mountains, shortly after the Sundering. Some time after then a flotilla of dwarven airships carrying refugees arrived. Some of the refugees left the flotilla and established a hold in the mountains, and began mining their ore and trading with the surface folks. The rest of the flotilla cast off, its denizens feeling more at home in the sky now than they ever did underground.
Some 200 years pass, and Hochmarch and New Middenheim grow into sprawling metropolises, that strain the resources of this tiny shard of land. The dwarfs have all but exhausted the once-rich veins of ore beneath their holds.
Just when things look most dire, a deadly warp storm rocks the plane. When the people come out of their shelters they find that their plane has collided with another, more than doubling in size.
An armed expedition is hastily arranged. The people of Hochmarch and New Middenheim send armed riders, while the dwarfs of the mountain holds send their best rangers. They venture out together into this newfound land, hoping that it will contain the resources their people so desperately need to survive.
And it does. The rivers are flush with spawning fish, the forests with great trees, the mountains rich with ore....and also swarming with orcs. They pour out of their warrens like an endless plague, and the men and dwarfs find themselves in the fight of their life. They've not known war in 200 years, but now must battle for their very survival.
Making matters worse they are not the only plan that collided with this one. A shard of Lothlorien has also found itself fused with this plague of orcs. But they have been lost deep within the eye of Chaos, fighting against an endless incursion of demons. Their society is a steel blade honed for war, and they have no use for the soft humans and dwarfs who have known only peace. The resources of this new land are theirs for the taking, and they will hear no objections from the envoys of the dwarfs and men.
The campaign is on! Arrange your
Mighty Empires tiles to represent this new land. Refer to the campaign book to see what plunder your people get from victory as you push into new territory, discovering ancient ruins or seizing a weapons cache from the enemy.