Well, they haven't recaptured their homeland from Sylvanas and the Gilnean Liberation Front is a thing, so no.
All that happened in the novel was Genn Greymane and Varian learned to understand eachother, and Varian took some Worgen and kicked the shit out of Orcs in Ashenvale. A good time, but they certainly didn't tie up many loose ends in the Worgen storyline.
Horde: Trolls, Tauren, Undead
Alliance: Worgen, Dwarves, Gnomes, Nightelves
everyone else got some attention recently
I'm gonna guess that you're an alliance player since your post is very one sided toward the alliance. So, first things first, they have always said that they want to keep the status quo between the alliance and horde thus making the gilneas story line dead in its tracks because in order for the gilneans to get their home back the undead (and horde) would have to lose which blizz doesn't want to do.
Secondly, the gnomes were a last minute add in to vanilla and thus are vey shallow which means there's not much they can do with the lore, and they also suffer from the same problem as the gilneans; blizzard wants to preserve the status quo.
Thirdly, blizzard has learned that putting a lot of art development and resources into building a functional capital city is not worth it because all the players will stay in the most convenient place, so fixing grim batol, reclaiming gnomeregan, rebuilding kezan, or founding a city in the undermine is a bit wasteful; not to mention the fact that the status quo comes into play yet again, the alliance have 4 racial capital cities and the horde has 4 racial capital cities, so if they let us reclaim gnomeregan then they have to give horde a capital city and that means more waste because unless they are the most convenient capital city then they won't be used.
Fourthly, giving an awesome story line centered on one race is very cool for people who like that race, but if you're not on that faction or don't like that race then it can be very unappealing to the player base as a whole thus lore that is driven by things going on in the world as a whole that gives incidental lore screen time to some races or classes has a much broader appeal rather than having a gnome-centric story line, goblin-centric story line, tauren-centric story line, worgen-centric story line, etc
Finally, shallow lore doesn't only affect gnomes, and so a lot of times it comes down to deciding if throwing in new lore or story to a race is better than touching on one of the many unresolved story lines such as Azshara and the naga, Ozumat and Neptulon, The Titans and the missing Titan mentioned in MoP, Tyr the missing guardian of Ulduar, Bolvar and the Lich King, Illidan being dead or not, Maev and her bigotry against magic using night elves, Anduin and the Army of Light, The remains of the Tomb of Sargeras, the Troll king and his sinking island, Old Gods, The other side of Azeroth (south of the equator), The opposite Karazhan where Sargeras did a lot of work through Medivh, The fey dragon ring in tirisfal and the other things going on there, The state of Kul'tiras, and many more completely untouched and unresolved story lines that are pre-existing that a lot of people want to see resolved.
They've given the factions victories over the other loads of times. The original Forsaken conquest of Gilneas is an example of that. If they want to have the Alliance reclaim Gilneas they can.