Blizzard has officially announced Seeds of Renewal which includes Dragonriding everywhere, reclaiming Gilneas and troll/draenei customizations.
This is presumably Patch 10.2.5!
The next update, Dragonflight: Seeds of Renewal, is in development and will allow defenders of the Dragon Isles to discover the buried history of Azeroth and the Dragon Isles through the Azerothian Archives Public Event, take Dragonriding to the skies of old-world continents, storm Dragonflight Dungeons alongside AI companions, complete new Campaign chapters in the continuation of the Dragon Isle epilogues, and more!
The skies of Azeroth and beyond can be yours in the saddle of your dragon. In Dragonflight: Seeds of Renewal, Dragonriding will be expanded to all old-world continents wherever flying is available.
Discover the history of the Dragon Isles and meet a unique cast of characters, hear stories of old, and witness the iconography of a time before. Participate in Solo and Group activities within Traitor’s Rest with a Weekly Public Event, plenty of opportunity to explore, and earn rewards like Battle Pets, Mounts, and a Transmog set.
King Greymane is ready to retake his kingdom, but Gilneas isn't as empty as expected. Help reclaim what was lost and return the kingdom to Gilnean hands.
Tank, heal, and DPS alongside follower NPC companions that join you on your Dungeon adventures. They will be available in all eight Normal Dragonflight Dungeons and can scale from 1–4 players. These companions will allow players to learn about Dragonflight dungeons at their own pace and provide the freedom to experiment and customize their Party makeup.